vA Font Global IDentifier (FGID) is used to identify a typeface. For example, FGID 2305 is assigned to
Helvetica Bold. Note that FGID 2305 applies to ANY Helvetica Bold typeface regardless of the language
complement being used.
vA Code Page Global IDentifier (CPGID) is used to identify a code page. For example, CPGID 1148is
used to identify code page T1001148.
vA Graphic Character Set Global IDentifier (GCSGID) is used to identify a unique collection (list) of
characters and is how the language complement is specified. For example, GCSGID 2039 is used to
identify the characters required to support the Latin1 language complement. Not that GCSGID 2309
applies to ANY Latin1 language complement regardless of the typeface being used.
Since a GCSGID simply identifes a list of characters, it can (and is) used in both character sets and
code pages. When used in a code page, the GCSGID identifies the list of characters contained in the
code page and is the value most commonly used in a GRID. The printers and PSF have GCSGID
superset/subset tables that are used to resolve the requested GCSGID down to a font that supports it.
vFont Width is used to provide size criteria. The FGID and GCSGID together provide enough information
to determine the typeface and language complement. Font width indicates which point size to use. Font
width, however, is not a point size value. It is based on 1440ths, a unit of measure commonly used by
printers and formatters.
GRID Width Calculations: For uniformly spaced fonts, the font width calculation is 1440 divided by the
pitch. Pitch is the number of characters that can fit in 1 horizontal inch.
Table106. Font Width Calculation for Uniformly Spaced Fonts
Width Pitch Calculation
240 6 1440/6
168 8.57 1440/8.57
144 10 1440/10
120 12 1440/12
108 13.3 1440/13.3
96 15 1440/15
84 17.1 1440/17.1
72 20 1440/20
For mixed-pitch character sets, the width calculation is the width of the 12–pitch space character (that is,
1440 divided by 12).
Table107. Font Width Calculation for Mixed-Pitch Character Sets
Width Pitch Calculation
120 12 1440/12
For proportionally spaced (typographic) fonts, the width calculation is one-third the point size converted to
1440ths of an inch. There are approximatley 72 points to 1 inch or 20 1440ths per point.
Table108. Font Width Calculation for Proportionally Spaced Fonts
Width Points Calculation
40 6 (6x20)/3
47 7 (7x20)/3
53 8 (8x20)/3
60 9 (9x20)/3
67 10 (10x20)/3
AppendixB. Font Information for IPDS Printers 175