Photoshop (PSD) File Format

I expect that most of my prepress manager friends in commercial printing will let me know, in threatening emails, that they’re unhappy that I have listed native Photoshop (PSD) files as output files. Indeed, PSD files are not my first choice when it comes to creating image files that will accurately and dependably print. But the truth is that our ability to use PSD files further along into the print production workflow, and even through to the final RIP and print process, has been dramatically expanded. Whereas once our page layout programs would not even recognize a PSD file, we can now place, edit, and even print them. I think the key is to know the benefits and risks of using PSD files, and then learn to manage those risks.

The reason why prepress managers don’t particularly like dealing with PSD files is their propensity for complexity. Native Photoshop files can, and often do, contain layers, layer masks, editable type, vectors, vector masks, and alpha channels with plenty of transparency. You see, this is a good news/bad news story. The good news is that PSD files can contain all these image elements. The bad news is that PSD files can contain all these image elements. This is good news for designers and photographers who want to maintain the full editablity of their files for as long as possible. And unlike in the first two decades of PostScript printing, you can now readily place PSD images into page layout documents (InDesign and QuarkXPress), and you can also control visibility for much of this layered content from within the layout application. By having access to these layers, you can control their visibility on the fly.

The bad news is for prepress managers. The presence of all these various image components such as layers and masks dramatically increases the complexity of these files. And if all these layers and masks are not simplified (through flattening) or removed to create a simpler file, prepress managers must try to process (RIP) all this complexity into printed pages. One of the most common image-related output problems that prepress managers struggle with is trying to properly process (RIP) and faithfully render the transparency relationships between the various image file components contained within PSD and other layered files.

Having all this editing control is great from a design perspective. But understand that the more-complex the PSD image is, the more potential problems you are likely to have during output. If for design reasons you need to use PSD files in your InDesign and QuarkXPress documents, then by all means do so—that’s why the capability is there. Otherwise, place simplified flattened TIFFs whenever possible. For trouble-free printing, create simplified, flattened versions of your initially placed layered PSD files before going to print. Accessing and converting your PSD images directly through InDesign and QuarkXPress is easy and fast; read on to see how!