User Guide

Making OpenType Fonts
687
FontLab and VOLT
Microsoft VOLT (Visual OpenType Layout Tool) is an OpenType feature
editor program developed and supported by the Microsoft Typography
group. The big benefit of this program is that it can support all the features
of OpenType including those that FontLab cannot handle. VOLT is based
on a completely different user interface and provides visual tools to define
substitution and positioning lookups.
You can get more information about VOLT at this location:
http://www.microsoft.com/typography/developers/volt/default.htm
VOLT stores OpenType features and lookups information in a text-based
format, which, during work on a font, is saved in special tables in a
TrueType font. When work on the font is done, these tables are compiled to
GPOS, GDEF and GSUB tables and intermediate tables are stripped from
the font file.
If this option in the Tools > Options > TrueType:
is switched on, you can open the saved font in VOLT and it will contain the
special tables that VOLT uses to store intermediate data and on export
these tables will be restored unchanged. This means that even if you start
work on a font in VOLT, but then realise that some glyphs must be
modified, you can save the font in VOLT, open it in FontLab, modify the
glyphs and return to VOLT to continue your work on OpenType features.