Printing Duotones and Spot Color


Printing Duotones and Spot Color

Printing Duotones and spot colors presents its own set of challenges. For example, in this book, the Duotones and Tritones were created by using two or three custom color inks. But the color section of the book is printed by using four-color process. So the Duotones and Tritones had to be converted to CMYK before printing, which can result in darker , less distinct colors than provided by premixed inks.

If you want to import your Duotone into another application, you ll have to save it in EPS format. Only EPS preserves Duotone mode s color information properly. If you save it in another format, the additional curves simply won t be recognized; only Ink 1 will end up printing. Spot color channels, however, are supported by PSD, TIF, EPS, PDF, and DCS 2.0 formats.

A special problem common to Duotone and spot color jobs is the difficulty in proofing. Most color proofers convert everything to CMYK when printing; custom ink colors simply aren t recognized. If you have Duotones composed of, say, black and magenta , things will work out fine. But a proofing device can t recognize those painstakingly chosen PANTONE colors unless it can read the color s CMYK equivalents. You have to fake it out by either renaming the colors (in which case you don t get a true color proof) or by converting it to CMYK (same result). This is part of the reason some printers are loath to work with Duotones; they feel as though they re working blind, because no real accurate proof is available to guide them.

The problem is similar but not quite as worrisome with spot colors. When you print a job with spot colors on your printer, a composite is printed, and the spot color channels print out separately only when you image film or plates. Once again, proofs can be created, but only by compromising the integrity of the color channels. When you choose Merge Spot Color Channels from the Channels palette menu, the spot color is converted to your image s color mode and blended in with the other channels. The spot color channels are eliminated at this point. You end up with a composite image incorporating your spot colors (now defined as RGB or CMYK colors). It s important to have the spot colors in the right order before taking this step. Different Solidity settings can produce different results when merging. Layered images flatten during this procedure. And once again, you run the risk of altering the color matching, because the CMYK inks reproduce colors differently than premixed inks. If you want a composite CMYK proof of the spot color image, always duplicate the file first. Print the duplicate image to your ink-jet or other proofing device and print the separations to an imagesetter or laser printer from the spot color original.

If you plan on importing an image with spot color channels into a layout or illustration program, you must save it in Photoshop s DCS 2.0 format. This is the only format that will enable other applications to recognize the individual spot color channels.

Hands On 6, which follows this chapter, will give you further practice applying these features.




Photoshop CS Savvy
Photoshop CS Savvy
ISBN: 078214280X
EAN: 2147483647
Year: 2004
Pages: 355

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