The Wednesday Format: EPS

A very commonly used file format that can support both bitmap and vector data alike

EPS stands for Encapsulated PostScript. It is a popular file format which is used for printing purposes. EPS files can contain both bitmap and vector data and this makes the format a versitile one when we talk about offset output. The EPS format belongs to the category of the standard file formats–those formats that are supported by the majority of graphics software and aren’t native to just one application.

Round one: AI VS EPS

In the article The Role of TIFF in Desktop Publishing I have mentioned that the PSD format replaces TIFF in many situations, though not in all of them. The Adobe Illustrator (AI) format can do the same in regards to the EPS format. Yet the PSD format is more widely supported by non-Adobe applications than the AI format, so designers are more likely to save vector graphics intended for “cross-application” use as EPS.

Round Two: TIFF VS EPS

If the EPS file format supports both vector and bitmap data, should we just use the EPS format for everything? After all it’s widely supported too. While EPS has its advantages, it is not always the best choice. EPS files cannot be compressed like TIFF and PDF files. When we talk about storage or when we have to send our artwork through the net, the size of EPS files can come in the way. The support of layers in EPS files is also limited and when in the case of the Photoshop EPS you can’t have layers at all.

A common misconception is that raster TIFF files converted to EPS will become vector files. That is not true. The format changes, the file size increases, but the data remains raster. The only way to “convert” a raster image to vector is to trace it with a vector program or re-draw it. The image then can and should be saved as EPS as if it is saved as TIFF the vector data will be converted to raster and there is no coming back. So when talking about raster images, such as photos, don’t choose the EPS format–it won’t make a difference when output and it will slow down the process and occupy more disk space. If you have a fair amount of vector data and raster data both in the same artwork, then you should consider using the EPS format or the PDF format. PSD is also fine, but the PDF format has some features that PSD doesn’t have. More details about this can be found in the articles Shall I Use TIFF or EPS to Print Bitmap Images? and Desktop Publishing With Photoshop PDF.

Now Onto the Technical Stuff

To know more about the specification of the EPS format, I recommend reading the following resources:

Encapsulated PostScript File Format Specifications (PDF) by Adobe Developer Support.
What Is Encapsulated PostScript? by the University of Cambridge.

If there are other resourced you think would be relevant to this article, feel free to suggest them by leaving a comment below.