EPS (Encapsulated PostScript Files) are strange bunnies. When you import them into your DTP or presentation program, they behave differently than the other imports you're used to. Here's the Why and Wherefore.

First of all, EPS is NOT the same as PostScript (such as you'd produce by printing to disk using a PostScript driver). It can contain nearly all the same commands and graphics as a regular PS file, but some PS operators are strictly verboten in EPS.

EPS contains no page setup information and might not contain a "showpage" command ... the PS equivalent of "Print 'em, Dan-o". An EPS may print if you send it to a PS printer. Sometimes you get lucky. But then again, it may not. Them's the breaks.

Neither is EPS the same as AI, or Adobe Illustrator format. AI is a very restricted subset of EPS intended for importing apps to translate into their own format, which is definitely not the case with EPS.

An EPS file contains one image only; in other words, it cannot contain multiple pages, but each image may include several other images.

What happens when you import an EPS file? First of all, let's use the term "place" rather than "import" since the mechanics of EPS are different from regular imports.

There are two general classes of EPS file, those with a preview image and those without.

If the EPS includes a preview image, then that's what you see when you place the file. The preview may be TIFF or WMF if you're working on a PC, PICT if you're a Mac user. Most Mac programs support TIFF as well. No PC apps support Mac-style PICT previews. If ever there was a hint as to which you should use if you're bi-platformal, that was it. TIFF. Got it?

If there's no preview image in the EPS, there's nothing for your app to show you.
Instead, you get a box that's the same proportions as the EPS file (the box size is derived from the %%BoundingBox comment that MUST be in every EPS). You may also see some of the other text from the header section of the EPS ... things like BoundingBox, Creator, and whatnot. Not very WYSIWYG, but more useful than a plain grey or white box all the same.

Note that your app makes no attempt whatever to interpret or convert the actual contents of the EPS file. This is Right and Proper behaviour.

Well. Unless your app happens to be part of Microsoft Office 2002 or later, that is. The Office EPS import filter actually attempts to interpret the PostScript contained in the EPS to create a preview image. This means that Word and PowerPoint 2002 and up may be able to display a preview of EPS files that other software might show as a gray box. On the other hand, interpreting PS can be time consuming, and you may prefer to turn this feature off, but you can't. Note also that if Office 2002 or later is installed on the same system as Office 2000 or earlier, the earlier version(s) will no longer be able to print EPS graphics to a PS printer. You'll need to print documents that include EPS from the later version of your Office apps.

At print time, one of two things happens. If you're printing to a PostScript printer, your app simply spits the contents of the EPS back out to the printer, surrounded by a few other commands to establish the scaling and position of the image. Again, it makes no attempt whatever to understand what's actually IN the EPS.

If you're printing to a non-PS printer, your app can't very well send raw PS out the port, since that would cause your printer to a) croak, or b) spew pages and pages of raw PostScript gibberish, or c) both of the above.

Instead, it sends the preview image, if there is one, or our old friend the empty box if there isn't. The quality of the printout will depend on the resolution of the preview image.

Some EPS have very low resolution, low quality previews, others may have full-color, high resolution preview images or even fully scaleable vector WMF previews.

Last updated 1/2/2005 2:15:07 PM

Content authoring & site maintenance by

Friday - The Automatic FAQ Maker