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.
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.