The Client’s Guide to Design

5

Print Design

With the rise and dominance of the Internet, it’s easy to think of ink-on-paper as an archaic technology, a relic of a lost world. But print’s not extinct quite yet—in fact, it continues to evolve.

Color

We’ll leave aside all the academic theory on the differences and similarities of print and web design, and concentrate on only those technical aspects that clients need to understand in order to be real partners in the design process. The first of these, and maybe the most important, involves the nature of color.

CMYK vs. RGB

The way color is reproduced in print is totally different from the way it displays on a monitor. Computer monitors are essentially the same technology as television screens, and they display colors as combinations of the three primary colors of light: red, blue, and green. This color model is known by the initials “RGB.” It’s an additive model: that is, the more of each color is added, the lighter everything becomes. One hundred percent of red, blue, and green displays as white.

Color reproduction for print couldn’t be more different: it is, essentially, the exact opposite. The color model is called “CMYK” after the initials of the basic ink colors used: cyan (which is the exact opposite of red), magenta (the opposite of green), yellow (the opposite of blue), and black. (Why “K?” Depending on who you ask, you’ll be told that it’s used instead of “B,” to avoid confusion with blue, or to stand for key, since the black plate is sometimes used as a key plate to align the other colors.) CMYK is a subtractive model: in order to achieve lighter tones, less ink is used. Given a background of white paper, white would be the total absence of any ink at all. On the other hand, one hundred percent of cyan, magenta, and yellow will produce black without even adding any black ink.

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In RGB (Image 1), as more hues are added, the color becomes lighter (in center)—because what you’re adding is light itself. In CMYK (Image 2), as more ink is added, the color becomes darker, eventually producing black (center).

What does all of this mean? The most important practical impact for clients to understand is that there are some colors that CMYK simply cannot reproduce accurately. CMYK is particularly lacking in its ability to reproduce greens, blues, and purples. The image below demonstrates how RGB can reproduce virtually any color, while CMYK (in circle) has limitations.

Ink…

Process Colors

The usual method of printing in color is termed “process color.” The process in question doesn’t involve mixing ink: the colors (usually CMYK) are successively laid on the paper in a gridwork of dots. Since the inks are transparent, wherever they overlay one another the colors will shift (for instance, solid yellow printed over solid magenta will make red). Still, it’s the eye that does a lot of the work of “mixing” the colors: adjacent dots of different colors aren’t perceived separately, but blend together. (We perceive pixels on a monitor in much the same way.)

Each of the four color grids, called screens, must be carefully placed at a particular angle in order to avoid what’s known as a moiré effect. This is an interference pattern that’s commonly seen whenever two regular patterns overlap (you can reproduce it by looking through two window screens placed one over the other). If the screens are placed at the proper angle (and in practice, they almost always are), they form a tight pattern called a rosette—which technically is also a kind of interference pattern, but is generally imperceptible to the unaided eye. Moiré patterns usually strike not because of negligence on the part of the printer (although that can happen), but because they’re trying to reproduce something that is already screened. Scanning a photograph that has been printed in process color, and then trying to reproduce it in process color, introduces multiple screen angles that inevitably results in a moiré. For this reason, clients should never supply scans made from already-printed artwork.

(Sometimes moiré patterns cannot be avoided—as, for instance, in the case of a photograph that has a small and regular pattern in it, such as a chain-link fence, or a plaid suit. The only thing that can be done in such cases is to retouch the photo, or substitute another.)

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The continuous tones of a printed photograph are an illusion…the image is actually made up of a grid of small dots in only four colors of ink (Image 1). If the grids are not aligned properly in relation to each other, what results is the interference pattern known as a moiré (Image 2).

A newer technique which avoids not only moiré patterns but screens themselves is called stochastic printing. In this technique, it’s not the size of the dot that determines the darkness or lightness of the tone, but the number of them: stochastic printing uses dots that are all the same size, and considerably smaller than most screens used in traditional printing. The dots are applied in an apparently random fashion, somewhat like photographic grain. This allows for a greater amount of fine detail, and makes it all but impossible for the unaided eye to perceive anything but smooth gradations in tone. It doesn’t, however, reproduce color any better: you’re still bound by the same inherent limitations of process color. It is also more expensive than traditional printing, requires specialized equipment and can be difficult to source. Whether or not it’s worth the extra trouble and expense is up to the individual client.

CMYK isn’t, however, the only process color system. Over the years, different process systems have been introduced using 5, 6, or even 7 ink colors. This increases the gamut—the size of the natural color spectrum that the system is able to reproduce accurately (CMYK can reproduce about 65%)—but introduces problems of its own, notably the multiplication of screen angles which might result in a moiré. Also, it requires specialized equipment and is more expensive.

A stochastic image uses tiny dots of color randomly placed, with no grid.

Pantone Colors

There is another color system in wide use in print design: the Pantone Matching System. If you’ve ever heard of a color referred to as “PMS thus-and-such,” you’re dealing with Pantone colors. Also called “spot color,” Pantone inks are actually mixed to match a certain color before being applied on-press. They can be screened like any other inks to simulate tints, and overprinted on other colors.

Pantone colors are very accurate; the entire point of the system is that any particular color mixed in Poughkeepsie will match the same color mixed in Phoenix, because they use the same specs and the same ink. On the other hand, this accuracy is expensive: printing a single shade of any PMS ink can cost more than using black, because you have to factor in not only material costs but also the time it takes to mix the ink and set up a printing press to use it. (Most presses are used to print either process black as a single color, or four-color process, and can move from one project to the next without pause. Printing a non-standard PMS color interrupts the workflow, and clients pay for the extra time involved in press setup.) Printing a PMS color as a fifth color—in other words, in addition to four-color process—involves setting up a fifth ink station on a press; or, on a press which only has four ink stations (which is most color presses), involves a second pass through the press. This increases the cost of the project by quite a bit; and again, it’s up to the individual client to decide whether it’s worth the extra time and expense.

One specialized use of Pantone colors is a “duotone.” This is an image that is printed using two colors, rather than just one ink or process color. (If you use three inks, it’s known as a “tritone.”) If done carefully, duotones can sometimes come close to giving realistic color; but even when both inks are used in equal amounts, duotones can give a richness to a photo that no single ink can match. This isn’t due entirely to the color effect, but also to the number of dots used. When using traditional screens, any single color will have a fixed number of dots for a given area. If two colors are used, that doubles the number of dots. (They necessarily will be smaller for each color, so the image doesn’t print too dark overall.) The increased number of dots allows for finer detail. In fact, when reproducing fine photographs in black-and-white, it’s not unheard of to use two, three, or even four plates, all of which print black.

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Sometimes, carefully-chosen Pantone inks can give a duotone almost the same impact as a full-color image.

…On Paper

Coated vs. Uncoated

The type of paper used for any project will also affect how the color looks. Papers are grouped in one of two major types: coated, or uncoated. There are significant differences in quality and character among papers in either category; but still, the main dividing line remains whether or not a paper has a coating.

Pantone recognizes this fact with its swatch books, which are divided between coated and uncoated paper samples. A comparison of the same ink on two different papers shows up the major difference: color on coated paper looks much more bright and vibrant. The reason is twofold. First, the surface of a coated paper is much smoother, like the surface of gloss paint. It scatters light much less than the rougher surface of uncoated paper, and so colors tend to look more saturated and brighter. But the coated surface also prevents the paper from absorbing much ink: uncoated paper is like a sponge. The ink doesn’t just sit on the surface, but is dispersed through the fibers of the paper. Paper without a coating is thus much more susceptible to what is called press gain or dot gain, which is a darkening of images due to the spread of the dot size as the ink seeps into the paper (remember: bigger dots, darker color).

Why, then, would anyone use uncoated paper? There are a number of good reasons, beginning with cost. Because adding a coating to paper is an extra step in the manufacturing process, coated papers are usually more expensive—sometimes significantly so. (Note: but not always—some premium uncoated papers are more expensive than the average coated stocks.) On a tight budget, an uncoated paper may be your only option.

Also, uncoated papers have their own advantages. They’re available in far more colors, textures, and finishes than coated papers. For some uses, it’s important to be able to write on the finished piece, and here uncoated paper is the only way to go. Perhaps the most important reason, though, is that printing is not merely a visual medium: it’s also tactile. Many, if not most, print projects are made to be held as well as seen, and the feel of the paper can be an important component of the impression it makes. Coated paper can be brilliant; it’s also slick, and sometimes this creates an emotional impression contrary to what was intended. If a budget will allow a cheap, thin coated paper, or a substantially heavier uncoated stock, it might well be worth using the uncoated paper and carefully adjusting the design and printing to suit the stock. The finished piece is likely to prove more impressive.

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When porous paper absorbs ink, the dots in a screen tend to spread. Larger dots means darker color—a phenomenon known as “press gain.” A color printed using a PMS ink (Image 1) can be roughly matched using CMYK (Image 2); but if significant press gain takes place, the resulting color will be noticeably darker and a poor match (Image 3).

Other Considerations

Offset vs. Digital

What most people picture when they think of a printing press is an offset press. Until recently, it was by far the most prominent type of commercial press in use. Offset printing involves creating a thin, flat plate onto which is etched an image of the final design being printed; the plate is attached to a roller, which contacts an ink roller as it spins. The inked image is then “offset,” or transferred, onto another roller, which in turn transfers the image onto paper stock being pulled through the press.

Digital printing, on the other hand, works very much like a scaled-up office printer. As with printers, it will use either a toner system or an inkjet system. In the first, rotating drums are electrostatically charged in order to create a copy of the image being printed out of toner (in the typical process colors of cyan, magenta, yellow, and black) on the surface of the drum. This is then applied to the sheet and fused to the paper by passing it through a heat unit. In the second, liquid ink is sprayed onto the paper rather than being applied by rollers.

In some cases (as with toner systems), the pigments being applied sit on top of the sheet, rather than soaking into it. For this reason colors applied digitally to uncoated sheets can be surprisingly vibrant, rivaling the look of ink on a coated sheet. Special metallic colors available for digital presses also tend to “pop” more than their offset cousins. On the other hand, PMS colors are not available for digital printing: they must be simulated using CMYK, which doesn’t always work.

Digital printing eliminates every pre-press stage between design and print—there are no films or metal plates involved, so the amount of human labor is drastically reduced. Despite this, digital printing is not inherently less expensive than traditional offset printing. One reason is that digital presses are much more limited in size (and hence, in the size of the sheets they can print on) than offset presses. For large quantities, it is almost always cheaper to print your project on an offset press (because you can print two, four, eight, or more copies on a single sheet). For smaller quantities—as small as a single copy—digital is the way to go. Digital printing has come so far since its infancy little more than a decade ago that the difference in quality is practically indistinguishable, so most commercial printers with both types of machine base their choice of technology strictly upon which is most cost-effective.

Proofing

For either type of technology, the proofs you are most likely to see nowadays are strictly digital in nature. It used to be that final designs were first committed to film (either through the use of an actual camera or, later, through a link between computer and imagesetter), and thus the first proof shown to the client was made directly from the same film that would be used to etch a printing plate. The use of film has been almost entirely eliminated from commercial printing through the development of direct-to-plate technology, and that means the step just prior to the creation of the plate is now the final design file itself—the same file for which the client should already have given approval before it even went to the printer.

But it’s inevitable that the printer will want to obtain another approval, even one that’s generated from the same file you’ve already seen and approved. For one thing, doing so limits the printer’s liability for any mistakes if you have signed off on them, so always proof carefully. But there are a couple issues that should be understood about proofs coming from the printer. First, it’s more expensive to make changes to the project the further along those changes are requested (another reason to always proof carefully, in order to catch mistakes at the earliest possible stage); and second, a printer’s proof can show with absolute accuracy the content and placement of the design elements, but it cannot guarantee absolute accuracy of color unless it’s a press proof—that is, unless it’s an actual sheet of printed paper, coming off the same press that will print the full project. If you’re printing digitally, the proof you see will more than likely be exactly this: since digital printing is cost-effective at the smallest quantities, the press also functions as a proofer. If you’re printing on an offset press, however, making adjustments to designs after a project has reached this stage is usually prohibitively expensive.

Local vs. Internet Vendors

There are many printing companies nowadays that specialize in dealing on a nationwide basis through their website alone: you upload the files, and they print and ship the finished pieces. To be brief: there is only one scenario in which it’s a good idea to deal with a printer over the Internet, and that’s if the price offered is all you can afford. Printing is not just a science (but boy is it a science), it’s also an art, and finding a printer you can rely on is a paramount consideration. Dealing with a local printer means having someone close by, available to hear your concerns and explain any problems; it means being easily accommodated if you want to see a press proof; and it offers the opportunity to establish a long-term relationship with a trusted vendor. Local printers offer a value-added service, and that extra value is peace of mind.