In the prepress world, most people don't print directly from Photoshopat least for their final output. Instead, they print from separation programs, presentation programs, or page-layout programs. In this section, we're going to focus on the latter item: page-layout programs such as Adobe InDesign, Adobe PageMaker, and QuarkXPress.
Our assumption here is that if you're printing from a page-layout program, you're probably printing to a PostScript imagesetter or platesetter, resulting in paper, film, or plates with black-and-white halftoned images.
QuarkXPress, InDesign, and PageMaker
In the last gasp of the twentieth century, QuarkXPress became the imaging tool of choice for graphic designers, service bureaus, ad agencies, and other heavy color users. Whether or not it deserved this title should be (and is) argued anywhere but here (otherwise Bruce and David would debate themselves into a tizzy). Currently, it appears that Adobe PageMaker is a dead product, and that Adobe InDesign is poised to take the crown from XPress sooner rather than later.
No matter which page-layout tool you use, it's crucial that you consider how your images will transport from Photoshop to the printed page. There are some basic rules you should follow.
Earlier in this chapter, we covered file formats in some detail, including which ones to use for page layout. To recap quickly: when it comes to printing from page-layout programs, always use TIFF, PDF, DCS, or EPS. With InDesign or QuarkXPress 6.5, you can also use the native Photoshop (PSD) format. We tend toward the TIFF format for almost all our files, though we'll occasionally use EPS or DCS for specialized effectssuch as duotones or custom screening. If your image has vector artwork (like text layers) in it, you should use EPS or (preferably) PDF.
CMYK vs. RGB
The choice between importing RGB or CMYK images involves two decisionswhen do you want to do your separations, and what program do you want to do them in? You can preseparate all your images with Photoshop (or another program), or you can place RGB images in QuarkXPress, InDesign, or PageMaker, and rely on their color management systems to do the separations for you.
Preseparating has a lot going for it. Images land on pages ready to print; the page-layout program just sends the channels down, with no processing at print time. Note that CMYK EPS files are not color managed in the page-layout program, though CMYK TIFF files may be. That is, if the page-layout program's CMS is turned on, your CMYK values may be altered at print time. To ensure the image data stays the same, choose an output (target) profile that matches the image (source) profile.
Placing unseparated RGB files has advantages as well, though. You can use the page-layout program's color management system to produce better proofs off color printers, and you don't have to target the images until the last minute, when you know all your press conditions and are ready to pull final seps. However, when it comes right down to it, we separate almost all our images in Photoshop first. (But we archive the RGB files, just in case we need to reseparate to some other target.)
Rotating large pixel-based images is a major pain on anything but the fastest machines. When you import an image into a page layout application and rotate it on the page, it seems to rotate very quickly. But the real math work is done at print time inside your PostScript printer. That means that every time you print (either a proof on a PostScript device or your final piece), your printer has to do the same time-consuming calculations that you could have done once in Photoshop. If you know you're going to rotate an image 15 degrees, do it in Photoshop first, then import it onto your page.
Cropping and clipping
Let's say you've imported a 24 MB photograph of your class of '74 onto your page, but out of 1,400 people, you only want to print the 31 people who were on the lacrosse team. You use the cropping tool (in PageMaker) or the picture box handles (in XPress and InDesign) to crop out everyone else, duplicate the image, recrop, and so on, for 31 people. And then you print the page....
If you saved the image from Photoshop as an EPS, prepare to wait a while for the page to print. In fact, you might want to consider a quick jaunt to the Caribbean. The entire image, no matter how much is showing, has to be sent to the printer for every iteration. Don't laugh. We've seen this plenty of times (usually in the same publications that are littered with gratuitous tabs and space characters).
On the other hand, if you saved the image as a TIFF, PSD, or a JPEG, the file shouldn't take too long because the layout apps can pull out just the data they need to image your page. However, it does take the program a little extra time at print time to throw away the data it doesn't need.
In either case, the page-layout program has to import and save a low-resolution preview of the entire image. That means unnecessary time and file size. The best solution: crop your images in Photoshop before importing them.
Both PageMaker and QuarkXPress let you perform some basic tonal manipulation on TIFF files. (InDesign does not.) In PageMaker (with grayscale images only), select Image Control from the Element menu. In XPress, select Other Contrast from the Style menu or use the QuarkVista palette to apply filters. However, this is like saying that your kitchen knife lets you perform heart surgery. Sure you can do it, but it's gonna get ugly. Except for special effects (and controlling screen settings on an image-by-image basis), we recommend that people simply not use these features; instead, use Photoshop.