Photoshop CC: The Missing Manual, 2nd Edition

Printing on a Digital Press

It used to be the case (and sometimes still is) that, when you prepared a document for a commercial printer, you would convert the images to the CMYK color mode before you inserted them into a page-layout document and certainly before you fired them off to the printing company. However, that process is changing because an increasing number of print shops now use digital presses.

Most digital presses work just like laser printers or copiers; they use electrostatic charges to transfer images from cylinders to the print surface. Like commercial offset presses, digital presses are primarily CMYK printers, but they use powdered toners instead of inks, which is why they can’t print spot colors. However, some digital presses, like the Kodak NexPress, actually do offer toner spot-color printing, but they’re limited to very specific colors like red, green, or blue. And rather than using these additional spot colors for special objects like logos, they typically expand the gamut of the CMYK toners, much like light cyan and light magenta do in inkjet printers.

WORKAROUND WORKSHOP: Printing Spot-Channel Proofs

Since only commercial printing presses use spot channels, getting them to print on your own printer for proofing can be…exciting. The solution is to pop into RGB mode temporarily and merge the spot channels. Here’s how:

To safeguard your original document, save it and then create a copy by choosing Image→Duplicate. Next, choose Image→Mode→RGB Color and then, in ...