type: string, default:
Font used for text. This very much depends on the output format and, for non-bitmap output such as PostScript or SVG, the availability of the font when the graph is displayed or printed. As such, it is best to rely on font faces that are generally available, such as Times-Roman, Helvetica or Courier.
How font names are resolved also depends on the underlying library that
handles font name resolution. If Graphviz was built using the fontconfig
latter library will be used to search for the font. See the commands
fc-match and the other fontconfig commands for how names are
resolved and which fonts are available. Other systems may provide their own
font package, such as Quartz for OS X.
Note that various font attributes, such as weight and slant, can be built
into the font name. Unfortunately, the syntax varies depending on which font
system is dominant. Thus, using
fontname="times bold italic" will produce a
bold, slanted Times font using Pango, the usual main font library.
fontname="times:italic" will produce a slanted Times font from
fontname="times-bold" will resolve to a bold Times using
Quartz. You will need to ascertain which package is used by your Graphviz
system and refer to the relevant documentation.
If Graphviz is not built with a high-level font library, fontname will be
considered the name of a Type 1 or True Type font file. If you specify
fontname=schlbk, the tool will look for a file named
schlbk.pfb in one of the directories specified by the
fontpath attribute. The lookup does support various aliases
for the common fonts.