EPS - Encapsulated PostScript
EPS is the print industry's old vector exchange format. It is a PostScript program with a header, and that header is where its metadata lives.
EPS stands for Encapsulated PostScript. PostScript is a programming language Adobe designed for describing printed pages, and an EPS file is a self-contained PostScript program describing one piece of artwork — encapsulated meaning it is written to be dropped into a larger document rather than printed on its own. For two decades it was how logos and illustrations were handed to printers, and it is still what many brand guidelines ship.
How an EPS stores artwork
The body of an EPS is code. Coordinates, curves, fills and strokes are expressed as PostScript operators in a stack-based language, so drawing a shape is a sequence of instructions rather than a data structure. That makes an EPS genuinely resolution-independent: the printer's own interpreter runs the program at whatever resolution it works in.
Two conventions make it usable inside another document. The first is the bounding box, a comment near the top of the file declaring the artwork's extent in points, which is how a layout program knows how much space to reserve without executing the program. The second is an optional low-resolution preview image, so the layout program can show you something on screen instead of a grey rectangle.
An EPS can also contain raster data, and often does — a Photoshop EPS is pixels wrapped in PostScript. The extension alone therefore does not tell you whether a file is vector artwork or a photograph, which is a recurring source of confusion in prepress.
What metadata an EPS carries
EPS metadata lives in the header, as specially formatted comments defined by Adobe's Document Structuring Conventions. They begin with two percent signs and read almost like a letter of introduction to the file.
The ones you will nearly always see are %%BoundingBox with four integer coordinates, %%Creator naming the application and version that produced the file, %%Title, and %%CreationDate. Prepress files often add %%DocumentFonts listing every typeface the artwork needs, %%DocumentNeededResources, %%For naming the person or organisation the file was made for, and %%Pages. Files produced by Adobe tools from the 2000s onward usually carry an XMP packet as well, holding document identifiers and an edit history.
%%DocumentFonts is the practical one: if a font on that list is not available where the file is printed, the output is wrong, and the list is the only warning you get. %%For is the one to check before reuse, since it frequently names a client.
Because the header is plain text, you can read all of this by opening an EPS in a text editor — the metadata is visible even when the artwork is not.
When to use EPS
Use EPS when something downstream demands it: an older prepress workflow, a printer's file specification, or a brand asset pack that has always shipped it. Within those constraints it works exactly as it always has.
For anything new, prefer PDF or SVG. PDF is the direct descendant of PostScript, keeps the same fidelity, previews properly everywhere and is far safer to process; SVG is the better answer on the web. EPS has no transparency support worth the name, its preview can disagree with what actually prints, and executing a PostScript program from an untrusted source has never been a comfortable idea.