Choosing File Formats Based on Workflow

There are so many different file formats that it's often difficult to know which one to use for each situation. Of course, every workflow demands special attention and there are always exceptions and special cases. However, for the most part, there are certain rules that you can follow, now that you really understand what each file format is capable of.

Print Workflows

When working in print workflows, designers traditionally use page layout applications like QuarkXPress or InDesign, utilizing file formats such as EPS and PDF.

Traditionally, EPS is used for moving files from Illustrator into page layout applications. However, with the ability to use transparency effects in your Illustrator files, the limitations of EPS become apparent. For example, as a designer, you know that Illustrator creates vector-based files that can be scaled infinitely because they are resolution-independent. You have always been able to save a file as an EPS from Illustrator, place it into an application like QuarkXPress, scale that artwork at will, and never worry about resolution or the quality of the resulting printout.

However, as you learned in Chapter 11, the process of transparency flattening may convert some vector content in your file into raster images, which are resolution-dependent. Because an EPS contains flattened information, you can't assume that an EPS file can be scaled infinitely in a QuarkXPress layout anymore. In fact, you have to think of an EPS file from Illustrator as you would an EPS file saved from Photoshopyou need to limit how much you can enlarge a graphic.

Although this is only a concern when your file contains transparency effects, keep in mind that there are many effects in Illustrator that you can apply that introduce the need for flattening (these are discussed in detail in Chapter 11).

On the other hand, native Illustrator files (which contain PDF 1.4 by default) have the ability to preserve live transparency, and therefore, flattening doesn't occur. When you save your file as a native Illustrator file, you can still scale that file infinitely, after it has been placed into a page layout application. But there's a catchyou need a page layout application that can flatten that transparency when it prints your file. That means Adobe InDesign. Refer to Table 12.2 for a list of suggested file formats, based on the page layout application that you're using.

Table 12.2. Suggested File Formats

Application	When Transparency Is Present	When Transparency Is Not Present
QuarkXPress	EPS, PDF/X-1a (PDF 1.3)	EPS, PDF/X-1a (PDF 1.3)
InDesign	Native AI, PDF 1.4	EPS, Native AI, PDF 1.4

Web Workflows

Choices are much easier to make for Web designers. Not because there are any fewer file types to choose from, but mainly because the use of file types is usually dictated by the technology that is being used. For example, if you want to create animated content, you know you're using a GIF file or a Flash file. Some sites are restricted as to what kinds of formats are supported (for example, not every Web browser can display SVG files), and so a designer is usually at the mercy of technology when it comes to deciding on a file format.

Although QuarkXPress can place PDF files, it can't correctly process PDF files that contain transparency within them. To avoid nasty printing issues, always place PDF/X-1a files into Quark, never into native Illustrator or PDF 1.4 files.

However, much can be done to a file before a final GIF or JPG is created. Therefore, you may find it beneficial to create your artwork in Illustrator, and then export it as a Photoshop file, which you can then edit and work on in other applications, like Photoshop, ImageReady, or even Adobe GoLive or Macromedia Dreamweaver.

Other Workflows

Of course, there are other workflows, including video, industrial design, architecture and engineering, fashion design, environmental designthe list goes on. With the information you now have about what each file format is used for, you should be able to develop a workflow that works for you.