Font definition files

The description of how L^ATEX font attributes are turned into TEX fonts is usually kept in a font definition file (.fd). The file for family <family> in encoding <ENC> must be called <enc><family>.fd: for example, ot1cmr.fd for Computer Modern Roman with encoding OT1 or t1ptm.fd for Adobe Times with encoding T1. Note that encoding names are converted to lowercase when used as part of file names. Whenever L^ATEX encounters an encoding/family combination that it does not know (e.g. if the document designer says \fontfamily{ptm}\selectfont) then L^ATEX attempts to load the appropriate .fd file. ``Not known'' means: there was no \DeclareFontFamily declaration issued for this encoding/family combination. If the .fd file could not be found, a warning is issued and font substitutions are made. The declarations in the font definition file are responsible for telling L^ATEX how to load fonts for that encoding/family combination.