1) PAPER SURFACE APPEARANCE

Smoothness
The smoothness is a measure of paper surface irregularities. The property affects many end uses, particularly the appearance of printing. The test is conducted by clamping the paper against a flat surface and measuring rate of air flow passing between the two surfaces. The Sheffield instrument is most commonly used, a higher number indicating a rougher sheet. Some typical smoothness values are: 10 -30 for very smooth paper; 100 -150 for smooth paper and 200 -250 for vellum paper.

Brightness
Aside from its aesthetic importance, paper brightness affects the legibility and contrast of printing. The brightness test measures the reflectance of paper under strict optical conditions and relates it to a white standard (Magnesium Oxide). This test is mainly applicable to white paper grades.

Opacity
Opacity is the lack of transparency that allows a sheet to conceal print on its reverse side. Opacity is greatly influenced by basis weight, brightness, type of fiber and filler. In testing, reflectance of paper is measured when backed successfully by a white body and a black body. The ratio of these two measurements determines the opacity reading.

Whiteness ¹

Finish
Finish is a complex paper property related to its smoothness. Paper can be used as it comes off the driers of a paper machine, or it can be machine calendered and later supercalendered. Uncalenered, machine calendered and supercalendered papers vary greatly in smoothness. The usual finishes of uncoated book papers are, in order of increasing smoothness: antique, eggshell, vellum, smooth and lustre. These finishes are classes together because all can be produced in the machine. Additional smoothness is obtained with supercalendering. Coating, of course, further improves the finish and smoothness. Some finishes are embossed on the paper after it leaves the machine. These are produced by a rotary embosser, a machine similar to a mangle, with the paper passing through it dry and under pressure. Commonly used embossing patterns are linen, tweed, and pebble.

2) PAPER STRUCTURE AND STRENGTH

Porosity²
The porosity is an indication of the openness of paper, as measured by resistance to the passage of air through the sheet. Two types of instruments are generally used to measure porosity - Gurley and Sheffield. The Gurley instrument measures the seconds required for a given volume of air to pass through a single sheet and is generally used for porous papers. A high reading indicates a less porous (or more dense) paper. Sheffield porosity measures the flow rate of air through a single sheet and is generally used for non-porous or dense sheets. A high Sheffield reading indicates a more open paper. A typical Gurley porosity test for 50lb. smooth offset would be 10-20 seconds.

Wax Pick ³
(Dennison) is a measurement of paper surface strength. This test evaluates surface bonding strength and relates to the tendency for tacky inks to pick fibers or particles from paper surface. To test for these properties, a series of waxes of varying hardness are melted, placed on the sample, and, after cooling pulled off. The softest wax (lowest number) that removes surface fibers designates wax pick number. A typical wax pick range for uncoated printing papers is 10-12.

Strength⁴

Formation
Formation is the physical distribution and orientation of fibers and other solid constituents in the structure of a sheet of paper which affects the appearance and other physical properties. Formation is also referred to as "look through" because the formation can sometimes be observed by looking through the sheet itself. A poorly formed sheet in which fibers are distributed unevenly will cause ink to absorb at different rates. The result can be a mottled appearance in which some areas may have blotchy ink show through.

Grain Direction: Long and Short Paper Grain
The direction in which most fibers of a sheet of paper lie is called the grain direction. As paper is formed, the slurry of fibers moves forward on the paper machine at high speeds, aligning the fibers in the direction of the movement and creating the grain. At the same time, the machine shakes the slurry of fibers from side to side, so that the fibers crisscross. This crisscrossing creates a web of fibers, and gives the paper strength in both directions, while maintaining a predominant grain direction.

As the moisture in the air changes, the individual fibers take in moisture and swell sideways, rather than from end to end. This explains why paper will expand or shrink across the grain, and why it is more flexible along the grain while it's stiffer against the grain.

Which Way Does it run?
For bound work, the grain should run parallel with the binding, creating a smoother fold, making the pages easier to turn, and allowing the paper to swell across the grain. If the binding runs across the grain, the free ends of the paper will swell or shrink with moisture changes, but the bound ends will not. The pages will buckle and the binding will weaken. The fold may also crack, creating a ragged edge, especially when the paper color shows through cracks in the printed surface.

With sheet paper, the grain direction is indicated by underscoring (or bolding) the dimension along which the grain lies, or by changing the order of the numbers. For example, a 23" x 35" sheet is grain long. Grain short is indicated by 23" x 35" (or 23" x 35"), or 35" x 23". The grain direction should appear last if not underlined or in bold. On web paper, the grain runs along the length of the paper web.

Generally speaking, paper that is run grain short (with the grain aligned with the press) will run more easily, because the paper fibers are aligned with the press. However, the fibers can be pushed outward causing registration problems. Paper which is run grain long will provide better registration, but has a greater tendency to curl as it passes through the press.

How Grain Affects Strength
Making a tear in a sheet of paper along the grain is easier than tearing a sheet across the grain. Tearing with the grain pulls fibers apart from each other, while tearing across the grain tugs at whole fibers, which have greater inherent bonding. Folding with the grain is also easier than folding across the grain. Folding against the grain may cause the paper to crack or buckle if it has not been scored first. Generally, lightweight paper does not need to be scored. It is usually best to score 100# text and all cover weight. Recycled paper is less apt to crack when folded against the grain, because the fibers are shorter and the bond not as strong.

To avoid problems with registration and runnability, it's always wise to let paper stock get acclimated to your pressroom's temperature and humidity before running it on your press. This is especially critical when paper stock is delivered from a mill or warehouse located in a different climate than your own. Because many mills are located in the North, printers in Southern climates are likely to experience problems if paper is not allowed to acclimate to local conditions.

3) STORAGE - TEMPERATURE AND MOISTURE
Hours required to temperature-condition paper*

*Official Chart by the Graphic Arts Technical Foundation.

Moisture
The moisture content of paper is affected by both the drying conditions when made and the relative humidity environment in which it is used. Ideally, paper should be made with a moisture content in equilibrium with the relative humidity where it will be used. Of course, environmental conditions vary at different places and times of the year. Ideal conditions seldom occur. If paper is drier than its environment, it will pick up moisture; and if lower it will lose moisture. Under extreme differences, these changes in moisture level will cause dimensional changes in the paper and cause problems such as curl, warp and waviness. Ideally, paper is in balance with an environment of 74°F and 50% relative humidity. To achieve accurate and reproducible results, exacting test procedures are followed to determine paper moisture. The sample is weighed, dried in an oven at 105°C and then weighed dry. The difference in weight is the amount of water in the sheet removed by drying. Paper is generally made to contain between 4% and 7% moisture.

Properly Storing Paper
Why worry? Paper is made mostly of wood fiber. For higher quality (non-groundwood) paper, the manufacturer must remove the natural "glue" - known as lignin - that binds the small thin wood fibers together. Proteins, resins, fats, etc. are also removed. What remains is cellulose fiber, an organic material. When the manufacturer puts all the cellulose fibers together to form a sheet of paper, it becomes a breathing entity affected by the environment surrounding it. Consequently, care must be taken in storing paper to assure proper performance.

Moisture is probably the biggest problem. Since paper may be on skids, cartons or tightly packed rolls, moisture will begin to be absorbed at the edges first, showing up as wavy edges. The paper has grown at the edges by absorbing moisture. The center portions of the paper, however, may not have absorbed any moisture yet. The result? Poor registration, feeding, curl, etc.

The opposite is also true. Paper shipped to a very arid area will lose or give up moisture to the environment. As it does, it shrinks. Again, the edge loses the moisture first and shrinks, while the inner core does not. Poor registration, feeding difficulties, etc. are the result.

Proper storage is the key. Paper should not be stored in direct contact with concrete or damp floors, near high heat sources such as radiators or near cold walls (especially cold damp walls). Never store paper in an unheated or low heated warehouse, especially in winter. To prevent moisture from leaching into the edges, never sit rolls on end on concrete floors.

Paper to the press. Never pull paper off a truck and take it straight to the pressroom! It needs to acclimate! When skids of paper are brought into the pressroom, bands and wrapping should remain intact until the skids have been placed at the press and the paper has reached pressroom temperature.

The same is true for rolls. Unwrap the rolls just prior to hanging on the back stand. The length of time required to temperature-condition paper depends upon the size and volume of the skid, roll or carton.

Care must also be taken when backing up a job. Moisture can influence the stack between printings if it's not properly stored, causing registration problems on a second pass.

Conditioning is also important for small printers who print or utilize cut-size paper. Paper which has absorbed moisture will curl upon passing the fuser system of copiers or laser printers. It is best to control the temperature and humidity in the areas where cut-size paper is going to be used to prevent excess moisture absorption. The ream wrap should not be removed until the paper is ready to be copied or printed.

To help prevent damage, movement and handling of paper should be minimized from its arrival until it goes to press.

4) ENVELOPE

Styles ⁵

Sizes⁶

5) HELPING YOUR CUSTOMERS DECIDE ON PAPER

Paper for corporate identity

Selecting the right paper for a company's letterhead, business cards and other communications is as much about character as it is quality. It's about figuring out who the company is, what image they want to project, and what paper best projects that image. Use this Tip Sheet to help your customers choose a paper that fits their own, individual dress code-and help them dress for success.

Figure out your Customer
A company's identity drives the "image" the company needs to project. Like a person, a company's image can be slick, or earthy, or elegant, and so on. How would you describe the identity of the company? Answering that question is the first step toward finding the perfect paper for the job.

Consider a Paper's Character
Now that you have a handle on your customer's character, think about which paper makes the best fit. Choosing paper is, in many ways, a subjective process that involves responding to texture, color, look and feel. That's why you should offer your customer a wide range of samples to examine.

Show your customer samples of writing, text and cover papers that come in many finishes and colors, from bright white to rich, dark shades.

Colors evoke feelings and affect how people perceive you. Rich, unique and complementary color systems have personality and appeal for both designers and corporate clients.

People respond to touch as well as sight. That's where basis weight and surface texture come in. Let your client handle a variety of basis weights in the 20-24 lb. writing range, as well as the 60-80 lb. text range. Also, let your customer sample a range of surfaces, such as laid, linen, smooth and vellum.

Ultimately, your assessment of a paper's personality is as subjective as the customer's. An 80 lb. terra cotta text paper with a vellum finish my suggest earthiness to one person, and modern chic to another. Don't worry - just keep a comprehensive paper sample library on hand and open this area of discussion. Your customer will appreciate the extra attention.

Letterhead
Ask what they plan to use the letterhead for: correspondence, bills, internal memos, reports, press releases?

Consider the ink to be used, and select a paper that will allow the type to be read easily. High-opacity text papers help readers concentrate and reduce eyestrain. Many letterhead papers call for one-color printing. Consider the effect a pastel or color paper will have on the ink. Paper can be part of the design. Will the letterhead be run through high-speed copiers or laser printers? Use heat-resistant inks and inform the customer that heat and pressure may damage thermography, engraving, foil stamping or embossing.

The elegance of watermarks reflects a professional image and lends prestige to a company's image. In addition, watermarks provide security,

Business Cards
Select a cover paper that coordinates with the surface and/or color of the paper used for the letterhead.

Here's an opportunity to make a bolder statement using a variety of colors that complement each other.

Direct Mail
Direct mail pieces receive a higher response rate when printed on eye-catching colors instead of white.

Newsletters
Use a striking color collection to help the customer plan different color issues throughout the year.

Choose a single paper system that offers wide variety in colors, so that single issues can be distinct and seasonal, but retain a coherent feel.

Selling Tips
Play consultant when a customer asks for a single job. For a run of letterhead, suggest matching business cards, envelopes and mailing labels. For a run of menus, suggest table tents or place cards.

For reports, manuals or catalogs, offer creative suggestions about using complementary cover papers or colors as section dividers. Use your imagination!

Why use colored paper?
You don't have to go to the expense of 4-color process to get colorful, attention-grabbing results. If you start with colored paper as a base, then add just a couple of colors, you can use combinations, screens and duotones to produce a piece that looks like it's four or more colors. The difference is dramatic. In fact, it's almost like cheating.

• Start with a colored paper that grabs attention and expresses the feeling you want to project. For example, yellow is bright and lively, whereas blue is calming.
• Pick secondary colors that complement the paper and work well when combined. Remember that the color of the ink will be affected by the color of the paper underneath.
• Combine colors to create another color. For example, red and blue make purple. Red and yellow would produce orange, while blue and yellow would make green.
• Punch up your headlines and emphasize key words and type by using different colors. Keep your background color in mind in order to avoid poor readability.
• Explore the endless possibilities for interest and variety that color halftones and duotones provide.

It's amazing what a little color can do. Using a few extra colors, you can turn an ordinary piece into something vibrant and exciting. Add quality, evoke an emotion, stand apart, be remembered.

Using Stock Creatively to Get More Bang for the Buck

Helping you build your business.
On many small- to medium-run jobs, the budget may not allow for 4-color process, expensive photographs or sophisticated techniques. You can still create greater impact for the piece by keeping the design simple while using the paper itself as a design element. In this way, you can use a one- or two-color press to save printing costs. Though the cost for colored and textured papers may sometimes be slightly higher than standard white, the extra expense will be offset by lower design, pre-press and production costs.

Here are a few ideas:

1. Use a colored paper that grabs attention and expresses the proper feeling. Yellow is bright and lively, for example, while blue is calming.
2. Pick secondary colors that complement the paper and work well when combined. Remember that the color of the ink will be affected by the color of the paper underneath.
3. Combine colors to create another color. Red and blue make purple. Red and yellow produce orange, while blue and yellow make green.
4. Punch up your headlines and emphasize key words by using different colors. Keep your background color in mind in order to avoid poor readability.

Explore the endless possibilities for interest and variety that color halftones and duotones produce

6) DIRECT MAIL

Direct Mail: Printed matter usually carrying a sales message or announcement designed to elicit a response from a carefully selected consumer or business market.

Best International Paper brands for Direct Mail:
Accent Opaque
Carolina
Springhill

Tips for Direct Mailers

• Mailing lists
• The Post office is your Ally
• Self-Mailer and Postcard formats
• Envelope Mailings
• Reply Mail
• Personalize mailing with laser or inkjet printing
• Ten Most common Direct Mail Mistakes

Mailing Lists
Every mailing starts with a list of targeted recipients. Here are some useful things to know.

Media and Formats
Mailing lists are typically provided in digital format and a variety of media, including magnetic tape, discs and cartridges or even files transmitted via the Internet.

Digital mailing list files are recorded on the media in a variety of ways. The method known as ASCII (American Standard Code for Information Interchange. Pronounced ask-ee) is most common. Database programs and spreadsheet programs are also frequently used. It's important to know in which format and medium a file will be provided to be sure it's compatible with the equipment doing the personalization.

A Capital Case Many databases and lists are provided in all upper case. That's due to the problems upper and lower case presents for computers. It's simple to convert an upper and lower case file into all caps. But it's probably impossible to convert an all caps file to upper and lower without a number of unavoidable mistakes. The computers just don't understand all the variations. That's why you may see a letter addressed to Ibm instead of IBM or Gmac instead of GMAC.

A list or a database works best when it provides separate fields for the first names and the last names. If the full name is in a single field, the computer makes a lot of errors distinguishing first from last. It is confused by names such as "Mary Ellen Van De Vere" and would likely call her "Dear Mary" (instead of "Dear Mary Ellen") or "Mrs. Ellen Van De Vere" (instead of "Mrs. Van De Vere").

Cleaning the List
Merge/Purge is a process in which the computer takes two or more different files of names and addresses, and creates a single file, making sure that any names on more than one source file go on the final file just once.

De-duplication is like merge/purge, but within a single list. It makes sure no name and address combination is on the list more than once. Again, it gets complicated due to things a human would recognize but a computer might not. For example, "Jim Jones, 123 E. Maple St" may not be caught as a match of "James Jones, 123 Maple." Still, de-duping a list removes a large number of the duplicates and thereby saves postage as well as other production costs.

Proofing the Data
Things can go wrong in personalization. Careful instructions and lots of checkpoints are vital.

After the data work, but before personalization begins, compare printouts of the source file with printouts of the output file to see that the proper data were picked up accurately. If the quantity of the mailing makes it practical, have a complete printout of both files and spot check records till you're positive it's all correct. Then check ten more. If the quantity is too large for a full printout to be practical, get the first few thousand and the last few thousand, and perhaps a block from somewhere in the middle, too.

Proof live samples of personalization on the printed mail pieces before full production begins. Again, check for correctness of the data. See that the position of the address information is correct and that it shows in the window of the mailing envelope no matter which way the envelope is tapped.

The Post Office is your ally

Classes of Mail
The United States Postal Service (USPS) offers several classes of mail. For direct mailers, the two of most interest are First Class and Standard.

First Class is the type used for personal mail at the familiar $0.34 per piece, up to one ounce. The USPS offers bulk mailers special discounts off that rate. The discounts are earned by sorting the pieces of mail into very specific sequences set by the USPS and complying with standards such as size, shape, printing and addressing.

All First Class mail is either delivered to the addressee, including forwarding to new addresses, or returned to the sender with an indication of why the piece was not deliverable.

Standard Class, formerly known as Bulk Mail, can be sent for under $0.20 per piece, depending on factors such as the quantity, density (how many going into particular geographic areas) and, again, the level of presorting done by the mailer. Standard Class mail is not forwarded to new addresses or returned to the sender. It's "abandoned" after one try at delivery. That's part of the reason it's cheaper. (NOTE: With a special endorsement, and for a fee, the post office will inform the mailer of the reason for non delivery. This address correction service can be valuable in keeping a database current.)

Non Profit is a form of Standard mail that allows qualified and certified charities and the like to pay an even lower rate per piece.

Postal Discounts
All postal discounts are subject to eligibility of the mailer, compliance with format requirements and presorting. Mistakes that may seem small can incur heavy increases in the cost of postage or even cause the mail to be rejected by the post office. For guidance, always contact the mailing compliance department at the post office location where the mail will be taken.

More Cleaning
Postal discounts also depend on the accuracy of the mailing list. The USPS has several list cleaning steps which are required to qualify for some discounts and smart to do anyway. The goal is to not mail pieces that cannot be delivered. That saves money for the mailer.

NCOA (The National Change of Address file) is maintained by the USPS from a variety of sources, mostly the Change of Address cards people fill out at the post office when they move. Discounts require the mail list be updated with the NCOA, or some other processes, within six months prior to the mailing.

CASS (The Coding Accuracy Support System) is another requirement for some discounts. Among other things, CASS checks the list for valid addresses and ZIP codes, correcting them where possible or rejecting the address from the mailing.

Paying Postage
Beyond the First Class postage stamp, there are other means of paying and affixing postage.

Meter: Both First Class and Standard postage can be metered on the envelope or other mailing piece. The meter has to be "loaded" with postage in advance of metering.

Indicia: An indicia is printed on the face of the envelope (or other mailing piece) at the same time the rest of the printing (return address, logo, etc.) is done. It requires a permit from the USPS and must be printed to a strict format. With an indicia mailing, the total amount of postage for the mailing must be submitted at the time the mail is turned over to the post office. Forms must also be submitted at mailing, so always check with the post office early. The mailing must be mailed from the same post office location which issued the indicia.

Pre-cancelled stamp: This is an actual postage stamp, similar to the normal First Class stamp but with a very different design. It gives the mailing a more personal appearance while still providing a lower rate than First Class on both presorted First Class and Standard Class mail. Payment of postage for a pre-cancelled stamp is handled just like an indicia mailing.

Aspect Ratio
The USPS requires mail pieces to be of a specific aspect ratio. Simply put, they have to be sufficiently rectangular. More precisely, the length (the direction of the address is the length), divided by the height must be between 1.3 and 2.5, inclusive. The template titled, "Letter-Size Mail Dimensional Standards Template" will help make the determination easier. (A similar template is also available from the USPS.) Mail outside the limit may still be mailable but will incur an additional cost per piece.

Weight
Be aware of the total weight of the assembled package, especially for First Class mail. The additional postage for a First Class mailing that hits one ounce can destroy the profitability of the program. Keep Standard Class mail safely under 3.3 ounces.

Tabs and Wafers
Many folded self-mailers require tabs to close the fold so it will feed through postal equipment without falling open. Always check with the post office in advance.

It Never Hurts to Ask
Always run questions and layouts past USPS personnel for approval. They're eager to help. They don't like to reject mail. But postal regulations change and may be subject to interpretation in some cases. Check the Postal Service Web site regularly for updated information and available literature: www.usps.com.

Address Float
Beware of "float" in the envelope address window. The post office will tap the submitted envelopes three times; down, left and right, and all of the address must remain visible in the window all three times.

Self-mailer and postcard formats

• A flat piece of paper is a postcard; folded, it becomes a self-mailer.
• A self-mailer or postcard may be no smaller than 31/2" x 5" in size. If either dimension is smaller, it will be rejected, even with additional postage.
• The maximum size to qualify for the USPS postcard rate on a single card is 41/4" x 6".
• Larger postcards cost more in postage, but can be a good investment because they stand out.
• A self-mailer or postcard can be as large as 61/8" x 111/2". If larger in either direction, it becomes a "flat," which requires more postage and may have other requirements different from "letters."
• There are minimum weights for postcard stock. Cards up to 41/4" x 6", must measure at least 7 pts. (.007 inch) in thickness. Cards larger than that must be at least 9 pts.
• The paper must accept laser printing (as well as handwriting of all kinds for response).
• White paper is best; light colors may be allowed. Contrast between paper stock and type must be high enough for postal equipment to read it. When in doubt, check with the post office.
• The printing inks must be laser-friendly.
• Metallic inks are not usable for laser printing. Metallic inks create problems with electricity in laser printing.
• Regular thermographic inks melt in laser printing. There are, however, special thermographic powders and curing methods that are safe to use.
• All printed pieces to be lasered must be delivered flat to the lettershop, not folded. The folding will be done after the lasering is completed.
• The bottom edge of a self-mailer must be closed - either as the folded edge or with tabs (wafers) - in order to feed through postal equipment.

Envelope Mailings

• The ideal outside envelope is the #10 window.
• A 6" x 9" or 61/2" x 91/2" window envelope can work well, too.
• Other sizes are possible, especially in large quantities, but beware of inserting equipment limitations.
• In large quantities, it is cost effective to print-and-convert, so most design options are open.
• When printing directly on finished envelopes in small runs, check on the limitations of registration, coverage and bleed.
• Outside envelope stock should be white or light in color (for the post office).
• Generally, no printing should appear below the top edge of the window.
• The letter and reply form can be a single sheet (81/2" x 14", for example) with the reply form perforated at one end of the sheet.
• With the letter/reply form combination, the letter can be personalized, too.
• The letter/reply form combination requires a reply envelope.
• #9 is the ideal size for the reply envelope with the preferred outside envelopes above.
• The finished size of all pieces has to be one inch less than the width of the outside envelope for automatic inserting equipment.
• The reply form should fit into the reply envelope easily by hand, without folding.
• The reply form (card or sheet) can be a separate piece.
• Again, white paper is best for contrast where the address appears; light colors can work. Check with the USPS.
• The printing inks must be laser-friendly. Metallic inks and thermography can cause problems.
• If the reply card is not personalized in advance of mailing, provide fill-ins for the responder.
• Allow only one personalized piece in the package (to avoid the need for expensive match mailing and reduce the potential for error and waste).
• For mailings to go First Class mail, keep the total weight safely under one ounce.
• Keep Standard Class mail safely under 3.3 ounces.
• The mailings can be heavier, but at a much higher postage cost.

Reply Mail

• Before printing any reply mail pieces, get USPS approval.
• Business Reply Mail (BRM) refers to a reply card or envelope, designed and printed to strict USPS regulations, which does not require a stamp. A valid business reply mail permit number is required. The original sender pays a fee, plus postage for each reply that is received.
• At least on the BRM format side, it's best to use white stock and black ink, but other combinations that provide sufficient contrast can work. Check with the USPS.
• A Business Reply Card (BRC) is the self-mailer form of BRM. Rigid standards apply to the paper weight and color, the size and the printed BRM format.
• Most of the requirements described in SELF-MAILERS and ENVELOPE MAILINGS apply to BRM too.

7) DEFINING BOND & WRITING GRADES AND THEIR OFFSET EQUIVALENTS (FROM "BEST IDEAS… - PAPER BASICS")

Though bond, by definition, is an office paper made for use in copiers and laser printers, it is commonly used by printers for letterheads, books, manuals, newsletters, sales sheets and mastheads. Mastheads are usually run on parent-sized sheets (11" x 17" or larger), then cut down to 81/2" x 11" for the end user to customize on their own office printers.

Writing is a grade similar to bond, but made with a shorter fiber, yielding a softer sheet which can be made with a variety of finishes and which accepts ink more readily. Writing is generally more expensive than bond and is used for higher end applications like company stationery. Some bond and writing papers have distinctive watermarks in the sheet.

Uncoated offset is made specifically for the rigors of commercial offset presses and is often used for the same applications as bond.

Bond, writing and offset come in the same actual weights, but are referred to by different grade classification weights.

8) PRINTING PAPERS VS. IMAGING PAPERS
Modern imaging equipment places strenuous demands on the paper it uses. Different types of equipment require different paper qualities in order to achieve optimal image clarity and quality.

Papers for Color Copiers: Color copiers are the cutting edge of imaging technology with faster speeds and excellent 4-color imaging. As a result, color copiers in the workplace are increasing rapidly. Paper for color copiers must contain lower moisture content to withstand the intense heat used in melting and adhering toner to paper. Hammermill® Color Copy Papers have an exceptionally smooth surface to handle heavy toner applications for exceptional color images.

Papers for Inkjet Printers: Inkjet printers use small jets that produce ink droplets, which are sprayed directly onto a sheet of paper. Paper for inkjet printers must be formulated with just the right smoothness to allow the ink to absorb and not smear or run. Hammermill® Jet Print papers are offered in coated gloss and matte finish, as well as an uncoated sheet.

Papers for Laser Printers: Laser printers are commonly found in the home office and business environment and are capable of producing exceptionally detailed images. Laser papers must be manufactured with a very smooth finish in order to run properly in a variety of laser equipment and must be able to handle even the finest detail. Since laser imaging also utilizes a heat process, the paper must contain a lower moisture content than typical papers to keep images looking crisp and brilliant. Hammermill® Laser Print has an ultra-smooth surface that feels polished and distinct, enabling the toner to lay down evenly, with no hills or bumps. In addition, laser papers are brighter than most copier papers, so images really stand out on the page.

Papers for High Speed Copiers: Copiers are the workhorse of business communications, and the paper used in this state-of-the-art equipment must perform flawlessly. High speed copiers produce a high volume of work in a short amount of time. A reliable copy paper must have the surface formulation to provide clear images and just the right smoothness to assure jam-free performance. Hammermill Tidal® MP is designed to resist moisture and curling at the edges, so it runs consistently and smoothly in both high speed copiers and plain paper fax machines.

Printing Basics 101

1) PRINTING QUALITY ISSUES

Ghosting
Ghost images are unwanted images, often faint, that appear in a printed piece. Mechanical ghosting is usually caused by conditions on the printing press and/or layout of the form.

Gloss or gas ghosting is a chemical type of ghost. It is the transfer of a printed image from the front of one sheet to the back of another (not through the sheet). Causes of gas ghosting include large solids printed on a back drop form, large lifts in the delivery pile of a sheet-fed process, or backing up the first side too soon after it is printed. Gas ghosting can also result when the ink drying on the second side is accelerated or retarded by fumes given off by ink on the first side.

Mottled
This term refers to the spotty, uneven or non-uniform appearance of a printed surface. It is also used to describe a nonuniform distribution of fibers in the formation of a sheet of paper. There are several different kinds of mottle, including ink mottle, gloss mottle, back trap mottle and wet trap mottle.

Ink mottle describes a blotchy, cloudy appearance instead of a smooth, continuous ink film on the press sheet. Mottle patterns are random rather than symmetrical and occur when the substrate or the coating does not absorb ink uniformly. Ink mottle is usually a result of poor paper formation, high paper porosity, too much dampening, ink too strong and insufficient ink is being carried, or water interference.

Gloss mottle refers to a galvanized ink appearance caused by poor paper formation. Areas of fiber and non-fiber result in ink soaking into some areas and not into others.

Wet trap mottle is caused by the overprinting of one color onto another with tones and solids. Wet trap is most apparent in high-contrast colors such as blue. The printed sheet will show light and dark areas in the affected print solid or tone.

Back trap mottle is the irregular and unwanted variations on ink density caused by uneven absorption of the substrate and printing in succession onto blankets with no overprint ink. Four or more color presses generally show this problem.

Milking
Milking is the result of carbonate and starch depositing on the offset blankets. This is released from the surface of the paper. Cleaning the blankets can be difficult with normal press washes. It is best to use warm water and solvent. The carbonate can also wear the plate over time or cause blinding which is the removal of the image.

Piling
Piling is described at the build-up of ink in the image areas of the ink rollers, plate or blanket which does not transfer. Piling, with uncoated papers, is usually caused by filler and/or fiber mixing with the ink, resulting in a putty-like substance. This putty-like material builds up in image areas and is forced to the edge of the image due to the rotation of the cylinders. This is known as ”tail edge piling.“ Some piling can build in the entire image resulting in a breakup of the image totally.

Piling is usually the result of issues with both paper and ink. Paper that is dusty with low moisture or poor surface resistance can contribute to piling. Also, ink which is over-emulsified or at too high an ink tack and fountain solution can add to the piling issue. Correction for this type of problem is not easy. One can work with an ink supplier to ”doctor“ the ink to reduce the piling tendency. The printer may also try adding a percentage of isopropyl alcohol to the fountain solution.

2) POST PRESS OPERATIONS, TREATMENTS

Embossing
Embossing is accomplished by pressing paper against a metal die under high heat. Embossing can be done with foil stamping at the same time. While most uncoated papers can be embossed, heavier papers allow for deeper and sharper embossing due to the thickness. When embossing different types of paper for the same job (e.g. text and cover), it is important to have the printer work in conjunction with the die-maker. By having this coordination of resources, the die can be designed with the greatest flexibility required.

Foil Stamping
Foil stamping, also called leaf stamping, will create a smooth opaque finish that contrasts with the texture of the paper. Stamping films usually come in two types: metallic and pig- mented. Metallic film stamps are cleaner on paper; however, pigmented films have a much wider selection of colors. While foil stamping is a fairly easy process, there are a few tips one should keep in mind.

• If foil stamping over text, watch out for tight kerning and narrow spaces between design elements. Foil stamping can bridge letters if too close.
• When stamping highly embossed papers, such as Beckett Ridge, care must be taken to insure the correct amount of pressure is applied against the foil and paper. In order to insure a good transfer off the foil, extra pressure is needed to compress beyond the embossed ridges of the paper. Some compensation will need to be made by the printer in order to insure that the foil does not feather.
• To avoid wrinkling, it is best not to stamp too close to the edge of the paper.
• Be careful in stamping over paper that has been varnished, as the foil may not adhere to the paper.

Folding
How well a paper folds depends mostly on its weight and the direction of the fold. While folding lightweight papers is not usually a problem, heavier weight papers will need to be scored.

Scoring is done on or off press by pressing the paper against a metal die or rule. This forms a ”hinge“ which helps relax the fibers and prevents them from pulling apart during the folding process. It is important to score so that the ridge of hinge is on the fold. This results in the paper being stretched less and the fold being stronger.

If saddle stitching, you may want to consider scoring the opposite way from that described above. The hinge from the scoring process can result in a ”bump“ on the inside interfering with the nesting of the signatures.

Folding with the grain will result in a smoother fold that will allow the publication to lay flatter when opened. Folding against the grain will result in a stronger fold but will cause the publication to ”mouse trap“ or close.

Scoring
Effective scoring techniques depend on the weight of the paper. Scores produced on letterpress provide better results on heavy weight text and cover sheets than those of litho scores or scores made on folding machines. The most effective of the letterpress scoring methods are rule and counter, wire and rule, and channel creasing matrix. Hot scoring will improve folding as well as reduce the possibility of cracking for difficult jobs.

Scoring issues usually occur when the scores are too narrow, too shallow, folded improperly, made with channels that are too wide, made with counters that are not registered, or made with paper that is too dry.

Below are a few guidelines that should avoid such problems.

• Scores should be made with the ridge or bulge inside the fold to ensure flatter folding and greater strength.
• The score width should never be less than the caliper of the paper. Generally, the thicker the paper, the wider the score.
• The end use must be considered when determining the width of the score. The width of the score must accommodate the bulk and caliper of the material inside the fold.
• Scoring should be performed separately from folding and other finishing operations.
• Scores should not be attempted on paper that has been dried out. It is important that sheets retain moisture introduced by fountain solution. Moisture can be retained by keeping the piece covered and minimizing the time between printing and scoring. If the paper has dried out, it may be reconditioned by running it through the press and analyzing fountain solution.

3) VARNISH AND AQUEOUS COATINGS
Varnish, aqueous coatings and UV (ultra violet) coatings are often applied to printed coated papers for protection or to enhance the appearance. Coatings are rarely applied to uncoated papers for two reasons:

1. Uncoated papers absorb ink, minimizing scuffing and the need for protection.
2. Coatings provide little visual enhancement on uncoated stock, as it is absorbed into the paper rather than staying on the surface. Aqueous coatings, which dry instantly, are sometimes applied to uncoated papers to put a dry coating over the ink so that the paper may be turned immediately for backside printing or taken directly to binding.

Varnish

• is a petroleum-based ink without pigment and should be treated just like ink.
• can be used in spot applications while maintaining tight registration.
• comes in gloss, matte and dull finishes.
• can be applied through any standard ink unit.
• can be applied in line to provide scuff protection, but the visual effect is not as dramatic as off line or dry-trapped varnish.
• Dryback will occur and may slightly affect the color of the ink and/or paper.

In line vs. Off line Varnishing

• In line varnishing applies varnish on the same press as colors while the ink is still wet. As a result, the varnish and ink combine, minimizing the visual effect.
• Off line varnishing applies the varnish during a separate pass through the press after the printing is dry. The varnish sits on top of the ink for maximum dramatic effect.
• Budget and quality are the issues here. Because off line varnishing requires a separate press run and additional drying time, it's more expensive. But the quality is better.

Aqueous Coatings

• are water-based, so they're more environmentally friendly than varnishes.
• offer visual results equal to or better than dry-trapped varnish.
• bring out more gloss with coated papers.
• dry clear, but may have a slight dry back effect. May yellow slightly (but less than varnish).
• come in gloss, dull, satin and matte finishes.
• cover the ink and dry instantly. The sheet can be turned immediately for backside printing or it can go directly to binding. (May be used on uncoated stock for this purpose.)
• work best when applied by a press with a separate tower designed to hold the coatings.
• are usually applied to the sheet directly from a blanket (not a plate) in a flood application. Spot aqueous blankets can be made, but they add expense and do not provide registration as tight as varnish. However, new technology is addressing these issues.
• may be applied from a standard ink unit, if there is no coater on the press. However, this requires a different aqueous coating with a lower tack. The appearance of gloss aqueous applied from an ink unit is comparable to tower applications, but matte or dull aqueous does not work well. Spot applications are not possible using this method. Also, more attention and maintenance is required as coatings can quickly dry on the rollers.

Special care should be taken to assure a good match between the ink and the coating. Alkalinity of the coating can affect some pigments used in inks. Check with your ink manufacturer.

UV Coatings

• require special application equipment.
• are dried by ultraviolet lights.
• are solventless.
• are the most expensive of the three coatings.
• provide very high gloss for maximum visual effect.
• are used mostly for coated grades.
• should use inks compatible with UV coatings - such as the new hybrid inks - for better performance.

For best results, an aqueous coating should be put down first when applied off line. Does not apply if running on a press manufactured specifically for running UV inks.

Coating to Change a Sheet's Finish
Coatings are used for scuff resistance and to minimize fingerprinting, as well as to create visual effects. Coatings, as well as paper, come in a variety of finishes. The coating finish can be matched to the paper finish (gloss varnish or aqueous on gloss stock to accentuate the gloss) or the coating can be used to change the finish of the stock (dull varnish or aqueous on gloss stock).

Why would you want to change the finish of the paper? Why would you put a dull coating on a gloss sheet, rather than just use a dull stock to begin with?

Opinions on this vary, but from a technical standpoint, the best print quality is obtained by printing on gloss-coated stock. Because the surface of a gloss sheet is smoother and flatter than the surface of a dull or matte sheet, (see the "Paper Definitions" section in the "Paper Basics" folder) the ink sits on the surface of the sheet better and yields a cleaner, crisper dot. Then, if you want the refractive quality of a dull surface for easier legibility or just for the aesthetics of a velvety feel, you can add a dull or matte coating over the printing.

This is an especially good technique to keep in mind when a dull or matte finish is desired, but the print project requires a sturdier or heavier sheet than most enamels offer. Carolina® Coated Cover is an excellent choice for a book cover because of its strength for binding and wearability, or for a pocket folder that will contain a lot of material and may require pockets with depth. Carolina® Coated Cover gives you the strength and heavy weight options not available in enamel covers and the smooth surface of a gloss sheet for optimum print quality. Then, by just adding a flood coat of varnish, aqueous or even UV, you can increase the gloss or decrease it to a soft dull or matte finish.

4) Typical Film or Plate Impositions
Work and Turn:
To print one side of a sheet of paper, turn it over from left to right and print the second side, using the same gripper and plate, but opposite side guide.

Sheetwise:
To print one side of a sheet of paper with one plate, then turn the sheet over and print the other side with another plate, using the same gripper and opposite side guide.

Work and Tumble: To print one side of a sheet of paper, turn it over from gripper to back, using the same side guide and plate to print the second side.

5) CUTTING CHART

Page sizes and number of pages that are available from specific press sheet sizes.

6) BLACK AND WHITE MAGIC

Customers who can't afford color still need great design work. That's where you can help. Use this tip sheet to show your customers how basic design tools can transform black and white into a spectrum of possibilities. After settling on a concept, employ this magic formula for making great designs:

• Choose an appropriate format
• Carefully select the elements to be used
• Skillfully apply proven design principles
• ...and infuse it all with creativity.

7) HOW TO WORK WONDERS WITH DESIGN BASICS

Choose a format
If a certain format (e.g., a brochure) isn't predetermined, choose the most appropriate one for conveying the message: Factor in the desired visual effect
Consider how much text and art must by included
Include practical limitations (e.g., the intended end use, size of the print run, and effect on mailing costs).

Select elements
The basic design elements are line, shape, type style, and texture. At least one element appears in every design, and all may be used in combination. (But the fewest you need to communicate the message!)

Lines are used to:
Organize a design
Bring together or separate elements
Lend decorative interest
Direct the viewer's eye
Create moods or feeling

Shapes are powerfully attractive and can take many forms, including those created by lines, shading, blocks of text, photos, and illustrations. Shapes are great for:
Attracting interest
Organizing or breaking up the copy
Leading the viewer's eye in a certain direction

Type styles convey different "feelings." For example, a display face is not likely to work well for technical material. Different faces for heads and body copy also can be used to stir interest. Type styles should be appropriate for the:
Message
Audience
Design concept

Textures should support and not detract from the message. They can include:
Feel of the paper (e.g., textured or smooth) Engraved, raised surfaces Objects in photos and illustrations (e.g., a satin pillow)

Apply principles
After the format and elements are selected, the elements must be arranged to create the desired effect. Our principles for working wonders with black and white design:

Contrast can give dramatic (or subtle) impact to a design. Begin by thinking in terms of opposites: large and small or black and white. Use contrast to:
Stimulate interest
Create a mood
Lead the eye
Support a text message

Value refers to the difference between elements in terms of lightness or darkness. Value is not the same as contrast (e.g., two 100% black lines, one straight and one curved exhibit contrast but not value). Black, gray, and white values are excellent for setting a mood or directing the eye.

Balance organizes a design and is naturally appealing, but: Absolute symmetry can become boring Sometimes it's more effective to balance a design through asymmetry Intentional imbalance - like a tightrope walker deliberately leaning to one side - can create a sense of dynamic tension

Unity is the result of making sure the elements work together to achieve the desired effect. Ensure unity by using:
Similar elements (without giving up the benefits of contrast)
A grid for newsletters, brochures, and other long documents

8) DIRECT MAIL: Personalize your mailing with printing

• The usual two best options for personalization are laser and inkjet printing.
• For mailings of any substantial quantity, have just one personalized piece to avoid match mailing.

Laser Advantages:

• Laser personalization can be nearly edge to edge, top to bottom, both sides.
• Resolution is high.
• Many type fonts are available. (For the outgoing addresses, avoid the unusual or get USPS okay in advance.)
• Variables of all kinds can appear throughout the lasered copy.
• Laser can include maps, photos, signatures, anything that can be scanned and printed.
• Some colors other than black are becoming available.

Laser Limitations:

• Typically, the flat sheet can be no larger than 17" x 11", depending on equipment.
• There can be no perfs, die-cuts or holes of any kind in the sheet if it is to be lasered.
• The sheet to be lasered must be rectangular and flat.
• Avoid creating blanks in pre-printing which must be filled in by laser later, such as check boxes. It's very difficult to register laser information with pre-printed information.
• The paper stocks and printing inks must be laser-friendly.
• Beware of metallic inks or thermography.
• Laser printing will not adhere to most gloss coated stock. Uncoated works best. Some matte coated stock will work, but always run a test first.

Inkjet Advantages:

• Inkjet can address a huge range of size, thickness and material.
• Inkjet can personalize nearly the entire length or width of the piece.
• Basic colors are available.
• Can print on most stocks, coated or uncoated, depending on the print quality one desires.

Inkjet Limitation:

• Inkjet can personalize on a narrow bar, no higher than 11/2"

DIGITAL PRINTING

Digital Printing requires no film or plates. Instead, digital information is fed directly onto the imaging units. Digital offers advantages for both commercial and office applications in speed, flexibility and customization unavailable with other processes.

Digital Technology
The range of technology varies greatly from the small, inexpensive home and office inkjet printer to high speed commercial digital presses costing a half million dollars. There are many small inkjet or laser copier/printer manufacturers in the market, but as you move up in capabilities, the number of devices available decreases. At the top end, there are only a few players such as Xeikon^TM, Indigo®, Xerox®, IBM®, Canon and Heidelberg^TM.

1) INKJET PRINTING
Inkjet technology is used today to image offset lithographic plates, as well as in home and commercial printers, color proofing, bar-coding, etc. Inkjet has become more popular as its resolution and print quality has increased. Inkjet provides better color tone reproduction than less expensive laser technology. However, inkjet printers cannot create a halftone effect because they "spray" small droplets of ink, rather than producing a clean dot. The industry is close, however, to developing new software that will allow the creation of halftone dots with inkjet for truer images.

(INKJET DIGITAL PRINTING^H>)

Inkjet printing technology uses jets of ink droplets driven by digital signals to print the same or variable information directly on paper without a press- or copier-like device. It has many desirable features for digital color printing.

• Inkjet is less complex than other digital printing technologies.
• It uses much simpler devices than other technologies.
• It does not depend on light sensitivity, lasers or LEDs for imaging.
• It can produce high quality prints, has low cost of soncumerables [what is this? Is this a real word?] and has silent operation

Two basic types of inkjets are

1. continuous jet in which drops are generated continuously and deflected to produce an image, and
2. drop-on-demand in which a drop is formed and emitted on response to an applied digital signal.

Continuous jets have three types:

1. charged drops are deflected electrically to form the image on the paper and uncharged drops are diverted to a gutter and are recycled
2. uncharged deops go to the paper, and charged drops go to the gutter and are recycled
3. all drops are charged and are controlled by electric deflection.

Drop-on-demand uses two types of printers:

1. piezoelectric
2. thermal inkjet systems

Piezoelectric printers use a voltage pulse applied to a piezoelectric crystal to generate a pressure pulse in the imaging head that causes emission of a droplet.

Thermal inkjet systems have two types:

1. bubblejet
2. solid ink/phase change

Bubblejet printers use resistive heating that causes the liquid ink to boil. This produces an ink drop and vapor that propels the drop to the paper.

Solid ink/phase change printers use heat to melt solid sticks of ink, and the phase changed melted ink is converted to drops that are ejected using impulses from a piezoelectric crystal. The drops undergo another phase change from liquid to solid on contact with the paper. The system is claimed to print on any paper with print quality equivalent to laser printers at lower cost.

Most of the color printer using inkjet technologies have prices under $10,000, and many are will under $5,000.

Industrial inkjet systems have been in use for printing variable information in packaging. A system has been developed for printing variable information in newspapers in single color at 1,000 feet per minute (fpm). A 4-color system has also been developed that can be printed at 200 fpm. The system uses continuous inkjet technology with a linear array of nozzles or jets in a printhead. The technology prints multiple levels of dots at each pixel location resulting in variable dot densities that have a contone appearance.

Large format inkjet printers are used extensively as proofers for checking color content, register, and imposition in CTP systems and for printing large displays for indoor and outdoor advertising. Two serious limitations of inkjet printing have been poor light fastness and water resistance of inkjet inks. New inks have been developed to correct both these conditions. Also there are inkjet inks to match SWOP colors, and UV curing inkjet inks for printing MICR, textiles, wall coverings and commercial signs anddisplays. Two other limitations of inkjet printing are slow speed and low resolution (600 dpi or lower) which are being improved.

Drawbacks
Inkjet technology can require the use of "special" papers since the ink is liquid. If a paper is highly absorbent, ink will penetrate quickly, resulting in low print density. If higher quality printing is needed, higher quality substrates are necessary.

Most inkjet inks are dye-based and fade over time. To keep the dye from fading when printing wide format for window or outdoor applications, the printed sheet should be UV (ultra violet) coated or laminated. This will increase fade time substantially. Some new pigment-based inks last much longer than dye-based inks. With the increased use of digital photography, there is also increased demand for light-fast inks. Water fastness may also be a problem, as inks may smear and fingerprint easily.

2) LASER PRINTING
Unlike traditional light which radiates in all directions, a laser is a thin, intense beam of focused light.

A laser copier or printer contains an electrically charged, light-sensitive photo receptor drum or belt. When the information is received from the computer (via a printer driver) the laser exposes the charged drum or belt in the areas which correspond to the image areas. This forms an image out of many tiny dots. The more dots in a given area, the higher the resolution. (Hence the term dpi: dots per inch.) The areas of the photo receptor that are exposed by the laser become oppositely charged from the rest of the photo receptor and will accept the oppositely-charged particles of toner (which is a powder). The toner adheres to the drum or belt in those areas exposed by the laser and is transferred to the paper. The paper is then passed through hot rollers or some other heat device to "melt" the toner and bond it to the paper. (This is known as "toner adhesion.")

Since the substrate is exposed to high heat, it must contain lower moisture than a traditional printing paper. If the moisture content is too high, the heat will tend to curl the sheet. A sheet with high moisture content also robs heat from the fuser rolls, which may reduce toner adhesion to the sheet. High moisture will also lead to poor toner adhesion, causing the toner to "block" or "ghost" when sheets are folded or stacked in piles.

Unlike inkjet printing, laser technology can produce screens such as halftones. Laser technology is also used today to create images on many of the newer CTP (Computer to Plate) systems. Lasers are also used in CTPress systems such as the Heidelberg Quickmaster™ or the MAN Roland DICOweb™ press which image the offset plate/cylinders on the press.

The best way to print high-end inkjet or laser is through a RIP (raster image processor). It can take the computer data and convert it to bit map data which the inkjet or laser can use more efficiently than digital data it receives via a printer driver. RIPs can be simple software systems or more elaborate software/hardware combinations.

3) COMPARING COSTS
Comparing pure digital (laser systems) to DI (digital imaging) offset presses produces some interesting contrasts. Originally, laser digital printing costs were thought to be static, meaning the first print cost is about the same as the last. This is not totally true. Ink on paper, however, does require make-ready charges making the first copies very expensive. As the run becomes longer, the cost goes down.

The "digital" offset presses that still use ink on paper cost more per copy at the beginning. However, at about 800 impressions, they become cost competitive with the laser digital technology. This comparison was figured on an eight-page brochure printed on 11" x 17" paper, four colors, both sides, collated, folded to 81/2" x 11" and stapled. (Data from the Rochester Institute of Technology, Rochester, NY.)

Offset printing can be competitive with laser digital technology. Why? Computer-to-plate systems result in faster make-ready times. In this case, computer-to-press (imaging plates on the press) reduces make-ready time since all plates are imaged in registration with only minor adjustment needed. The CTP systems that are integrated with the press computer systems pre-set the ink system based on pre-press data. All this has greatly reduced the printer's make-ready times.

4) VARIABLE IMAGING
Some digital equipment allows the flexibility to make each sheet different, for the ultimate in customization and personalization. For example, an auto dealer can send digitally printed service reminders to his customers, including their name, mileage, recommended service and even a photo of their auto model, with different service "specials" based on their personal profile. This high degree of customization can be an effective marketing tool for your clients, allowing them to speak "personally" to each and every customer.

5) PROS AND CONS

• Offset printing allows more control over color. In digital printing, the digital information controls the density of the colors being printed. Very little adjustment can be made. In offset printing, the printer has more leeway in making color adjustments on a broader scale.
• Offset printing is capable of process and/or match (flat) colors.
• Most digital printing equipment offers process colors only. (Some match colors cannot be matched exactly in process.)
• Offset is preferred for handling solid coverage, vignettes and screens which have a tendency to streak and band when printed digitally. (Although this varies with equipment and quality is constantly improving.)
• Some digital printers and presses are limited in the kinds of paper stock you can use, because of inks and dyes used in the process. Some work better on coated; some on uncoated. Others require a special coating on the paper to produce the desired print performance.
• Sheet size is also more limited with digital equipment.
• Digital Printing is faster. There's no separate proofing, no film or plates, and little make-ready time is needed.
• Offset presses that still use plates are more expensive and require time to make plates.
• Hanging plates (if required), as well as adjusting color and register adds time and expense to make-ready.
• Offset requires a separate proofing process. With digital, the printing is the proof.

6) WHEN TO USE DIGITAL
Digital printing is excellent for personalized work, short runs (about 1000 impressions or less) and quick turnaround. As the quantities go up, digital generally becomes less cost effective.

1. Consult your supplier before using vignettes, screens and solid colors. They can cause streaking and banding, depending on the equipment.
2. Check on paper and equipment size limitations.
3. Stock choices may be limited and vary with equipment.
4. Consult your supplier regarding finishing and bindery capabilities. Most can fold and trim, but may not be able to perforate, die-cut or perform more complicated finishing or bindery operations.

7) IP DIGITAL GUARANTEES AND RECOMMENDED BRANDS
To assure your peace of mind, as well as optimum results, International Paper guarantees many of its papers to have the correct finish and moisture control characteristics to take digital images without jamming your printing equipment and at the same time, produce outstanding print quality. You can use these stocks for digital printing with complete confidence. Check with your International Paper merchant for specific guarantees.

Best Papers For Digital Printing:
Accent Opaque
Great White
Hammermill

8) ECONOMICS OF PLATELESS DIGITAL COLOR PRINTING

The short-run color printing market consists of color printing in quantities, usually, under 2,000, of variable information, on-demand and/or distributed printing. Serving this market world-wide are over 5,000 digital color presses which include mainly the liquid toner single unit digital offset press, dry toner 8-unit digital web press and 4-drum digital color copier systems. For runs over 500 the digital presses are supplemented by over 1,500 direct imaging (DI) computer-to-plate on-press systems.

A major difference between plateless and plate printing systems, besides the ability of plateless systems to print variable information from impression-to-impression, is the unit cost of printed products. In plateless printing, the unit cost remains approximately the same for any quantity of prints; i.e. the cost of 100 prints is about 100 times the cost of one print. In plate printing systems, the unit cost of prints decreases as the quantities increase. The break-even point for 4-color prints of pages (one side) between plate (with on-press imaging) and plateless printing is between 300 and 500 prints. The break-even point for CTP and plateless prints is about 1,000 prints, and for conventional platemaking and printing is about 2,000 prints.

10) DIGITAL LASER PRINTER COLOR PRINTING SYSTEMS

Laser printers date back to 1978. Early systems suffered from low resolution (300 dpi and lower). In 1989, a 600 dpi single color laser printer was introduced that is capable of printing 135 documents up to 11"x17" size per minute. The first color laser printer was introduced in 1995, and since then a number of OEM laser printers are being used by over ten manufacturers to produce digital color printing systems with resolutions as high as 1,200 dpi and speeds up to 60 ppm (4-color) and 200 ppm (monochrome). Most of these color laser printers less for less than $10,000.

11) DIGITAL COLOR COPIER PRINTING SYSTEMS

When a color server or controller is added to an EP color copier the device can be used as a digital color printer for short-run color printing (1-2,000). The first color copier used for digital color printing was shown in 1990 using a PostScript controller. There are thousands of color copier printing systems now in use worldwide. Three main types of systems are:

• One type uses new 4-drum imaging engines that can print from 31 to 40 color pages per minute (one side) with 400 dpi resolution and 6 to 8 bits per pixel color print quality. These systems with color servers cost less than the presses.

• A second system uses clusters of two, four, or six unit configurations of single color and 4-color EP engines driven by a special server, RIP and OPI software. A unique feature of this system is its job parsing software that allows each unit to operate as a single output device. When the job is completed, the printed stacks for each unit can be combined to produce a properly collated product. Cost of a 4-unit system is about a third the cost of the 4-drum systems.

• The third type uses modified single drum EP color copiers equipped with color servers. These have resolutions of 400 to 600 dpi and print 3-7.5 pages per minute (ppm). As of the year 2000, manufacturers produced over 20 types of color copiers equipped with color servers to produce color printers.