- Font not displaying in application (characters not showing up although font has been selected).
- This effects fonts shipped prior to 20 January, 2008. It may be caused by applications not supporting non-1000 UPM values in CFF OpenType fonts. There is no restriction on UPM values in the OpenType specification, although there effectively was in Type1 fonts, which were 1000. Since most CFF OpenType fonts (.otf files) are derivative of these older Type 1 fonts, and new fonts are by default 1000 UPM, applications may not correctly support this, although they will with Truetype OpenType fonts (whose most common UPM value is 2048).
Notable non-conformity to the specification in this regard may be seen in OSX Font Book, TextEdit and Suitcase Fusion.
The value of 2048 was used for Restraint because it afforded a higher definition grid to work in and allows greater fidelity in the fine strokes in the design.
If you are experiencing display difficulties, you may request a new build of the font which addresses this by reducing the UPM value to 1000. This affects the fidelity somewhat, but will probably not be noticeable by most people.