9.4.1.2 Type1 PFB fonts
PC Type1 fonts can be stored in a compressed binary format, called PFB.
These files can be unpacked as they are being downloaded to the PostScript
interpreter. The file is conceptually divided into segments, each of which has
a small header containing a “type” field and length
information. There are three types of segments:
- TYPE 1: ASCII text. This text can be sent directly to the printer without
any decompression.
- TYPE 2: This is binary data that should be converted to hexadecimal and
transmitted to the printer as a stream of ASCII hex data (new lines can be
inserted anywhere in hex streams, if necessary).
- TYPE 3: End-of-file indication. This is a flag that indicates that the
end of the data segment has been reached.
The detailed reference can be found at http://vrr.ucw.cz/doc/Download_Fonts.pdf.