EPS File Format

EPS used to be a more widely used file format for pixel-based images in addition to its previous and current use for saving vector images out of Illustrator. Many early RIPs preferred the EPS file format even though it is larger in file size than TIFF. Any clipping paths or other vector-based contents such as type had to be saved in EPS format because early versions of TIFFs did not support clipping paths or vectors. But with the new TIFFs’ flexibility and smaller file sizes, EPS files are used mostly now for these purposes:

◆ Saving vector-based images, such as vector logos, out of Illustrator.
◆ Saving multitonal pixel-based images, such as duotones, out of Photoshop. Currently only EPS
is equipped to store the multitonal transfer functions that control the ink densities on output.
◆ To save separated pixel-based spot colors as special-version EPS format DCS 2.0 (covered in
the next section).
◆ To save an image so that it cannot be altered (downsampled or compressed) during other
production processes such as normalization/distilling to create PDFs. For example, I use
EPS to protect my low-resolution, low-bit-depth screen grabs from downsampling and
compression.
◆ Some RIPs still prefer to process EPS files. But in this case, EPS is mostly used to save whole
pages out for RIPping and imposition, and is not used for saving individual pixel-based
images out of Photoshop.