What is an .afm extension / file?

Posted January 23, 2005

A .atm file stands for “Adobe Font Metrics”. Here is a definition that I found on this site called faq.org. Basically an .atm file is for storing readable data about the font metrics that a regular person can understand. Kind of like a structural guideline for how the makeup of the font should appear.

Here is what that link says…

AFM is Adobe’s ASCII-based file format used for storing font metric data as human-readable data. AFM is the standard Adobe font file format. This format is also known as the Adobe Multiple Font Metrics (AMFM) and Adobe Composite Font Metrics (ACFM) file formats.

In fact, AFM, AMFM, and ACFM are actually three variations of the same format. AFM files contain base or composite font information. One AFM file is used per master design of a font. AMFM files store control and global font information for a group of AFM files.

And ACFM files contain the global metrics of the composite font program. The specification for the AFM format is: Adobe Font Metrics File Format Specification (Version 4.0), Adobe Developer Support, 14 February 1992, P/N LPS5004. This document available via FTP as a Tech Note in PostScript format, or as hardcopy when obtained directly from Adobe (see the PostScript section for information on how to contact Adobe Systems, Inc.).