Vector artists get a lot of options. CorelDraw, Freehand, Illustrator, Inkscape, Intaglio, Xara X, architectural CAD, 3D modeling programs... you could use a different editing program every day of the week. Each one has its own features and interface strengths, but we're not here to talk pros and cons. If you're a stock artist, you need people to use your work, and that means creating vector files that work in as many different programs as possible. We're going to make you compatible.

All vector programs work in the same way, creating points that make up lines and shapes called paths. However, not every program can open every file. A current Freehand file can't be opened into Illustrator in an editable form. Likewise, you can't take a current Illustrator file and open it into Freehand. So how can you edit a vector file in a different program?

Enter the EPS (Encapsulated PostScript) file format. Created by Adobe, EPS files can work in a number of different programs because of some basic built-in restrictions. Plus, EPS files can be placed into page layout programs such as Quark and InDesign. PostScript files have been around for a while now, about 20 years. The current version of Adobe Illustrator uses PostScript Level 3.1. Unfortunately PostScript Level 3.1 files can't be opened by some programs, so we'll need to journey back in time - a whole decimal point, to PostScript Level 3.0, last found in Adobe Illustrator 8.

It doesn't sound like much of a jump down, but for non-Illustrator users, the decimal point makes a big difference. Not much has changed vector-wise from Illustrator 8 to now (we'll talk about some of these changes later), but almost any EPS file saved from Illustrator 8 will open into other vector editing software. If you're ever working on a vector file that's destined to leave your computer, it's a good idea to downsave your files to Illustrator 8 or lower, just in case someone using a different software program needs to edit the file.
What if you're not working in Illustrator, and can't downsave as a version 8 EPS? Easy. Save your EPS file, and then open it into any text editor (like NotePad on PC, or Text Edit on a Mac). What you'll get is a bunch of garbeldy-gook, lots of weird numbers and odd looking text. Ignore everything except for the first line.

The top line of text in your file should say something along the lines of "PS-Adobe-3.0 EPSF-3.0". As long as your file reads the numbers '3.0' or lower, you've got a PostScript Level 3.0 file, and it should be editable in other software (we'll get to some exceptions to this later). If your opening line of text reads '3.1', then you'll have to go back and tinker with your EPS export settings to find one that'll save in the proper file format.

Now we have an AI8 compatible EPS file, saved from whatever vector program we're working with. But this doesn't mean your file is ready to get out there and meet anyone. Depending on how you built it, there could be a lot of different editing programs it just doesn't get along wtih.

Adobe Illustrator 8 is not exactly a cutting-edge program these days. As a matter of fact, many versions of AI have come and gone since AI8 was in use, each one improving upon the last version. The newest version of Illustrator is CS2 (number 12 for those who keep count). Of course, an AI8 EPS file will open fine into CS2 (and most other programs). But a lot of the neat features currently available to vector illustrators simply weren't around when AI8 was.

AI8 didn't have all the cool transparency effects that show up in later versions. Stuff like drop shadows, layered transparent objects, glows, blurs, etc. When you try to save a file full of these effects down to PostScript Level 3.0, very strange things can happen. The fills of your file might rasterize and become non-editable, and appear pixellated when viewed up close. Your file size might also increase dramatically. There have been occasions where a 1 MB AI file will downsave to over 300 MBs as an AI8 EPS. Transparent objects can also cause your shapes to break open.

The shapes in your illustration may also split into several flattened shapes, making it very difficult to, say, change the colors in the blur that looked so great when you built it in AI CS2. So if you're planning on saving an AI8 compatible EPS file, you should avoid transparencies altogether as you build, or flatten and trim your transparencies before you export. You can do this in AI under the Object menu. Choose 'Flatten Transparency', and when you're done, run the shapes through your Pathfinder's 'Trim' function to make sure everything is closed, and nothing weird happened when you flattened the fills.

Just in case you've forgotten where the transparent shapes in your image are (and vector files can quickly get very complex), Illustrator offers an excellent preview feature. Go to 'Window' in your main menu and choose 'Flattener Preview'. This allows you to highlight every area of your file that uses transparencies (as well as some other stuff like expanded patterns or outlined strokes). Use this preview option to identify any potential 'trouble' areas in your image, and fix them before you export your file.

Gradients also cause compatibility headaches. The gradients you create in Freehand and certain 3D rendering programs don't work very well in Illustrator. When a Freehand EPS opens into Illustrator, the shape slices itself into dozens of tiny pieces, making it a huge pain to edit. This slicing can cause problems when you export the EPS file as a PDF, or rasterize it into a program like Photoshop. Sometimes tiny white gaps will appear between each shape, making your smooth gradient look like it's behind a venetian blind. If you're working in a program other than Illustrator, it's a good idea to steer clear of gradients altogether.