Microsoft VOLT

Microsoft VOLT is a lightweight software application developed by Microsoft for helping you add OpenType layout tables to fonts with TrueType outlines. It comes with support for a wide range of substitution and positioning types and a proofing tool for reviewing table lookups.

User interface

The GUI cannot be described as highly intuitive so less experienced users may need extra time in order to get used to working with it. The layout is divided into several panels that allow you to process scripts, languages, features, lookups and glyph groups.

Importing/exporting options

Microsoft VOLT gives you the possibility to add files in the working environment using only the built-in browse button, so you cannot rely on the drag-and-drop support. You may import/export data from/to TTF or OTF file format.
The program lets you add glyph data from glyph range or Unicode values, lookup definition (VTL file format), group (VTG file format), and PostScript names. Exporting options are available for glyph data, lookup and glyph project.

Work with OpenType layout tables

You may add scripts, languages, features, positioning, substitution, and glyph group, open the glyph editor and perform searches by name or Unicode value of the glyph, activate the proofing tool for checking out the result of applying layout table lookups, as well as compile the current project.
The application allows you to use extension lookup and apply the glyph settings for all fonts (e.g. you may activate grayscale and modify the size of grids, presentation and positioning).

Bottom line

All things considered, Microsoft VOLT comes with a decent feature pack for helping you add OpenType layout tables to fonts with TrueType outlines.