I am having difficulties solving a problem that is intriguing me for quite some time. The problem is the following (trying to provide as much info as possible):
At work we have a font file (.ttf) with symbols. There was a need to change one symbol, related to "B", U0042, so I installed FontForge and changed the graphics of the symbol using an SVG image. Then I saved it as a new font file, installed the updated font and checked if the symbol was changed. And it was. So far so good, I thought.
However, it turned out that all symbols in an InDesign document disappear when I use the new font. I started to investigate this, and I found the following:
In all InDesign documents, the symbols were defined using Unicode in the range F000 - F0FF (This is the Unicode Private Use Area) instead of 0020 - 00FF. When you enter "B" using the keyboard you get U0042, however when you use the Glyph panel to insert a character it identifies the symbol corresponding with "B" as UF042, and it inserts UF042. Surprisingly, however, the symbol is displayed correctly using the old font, both in the glyphs panel and in the document.
Now when you load the updated font file, the symbols are identified as in the 0020 - 00FF range, i.e. not in the PUA. On one hand this is consistent with FontForge, but on the other hand all our documents have defined the symbols in the PUA, and remapping them is quite a task. I suspect that FontForge must have changed something to the font file that prohibits InDesign to "see" the glyphs in the PUA.
Three other observations that may be relevant are:
1. The old font filename is presented in FontForge with (MAC) so I think the .ttf file was created using a MAC, but we use it in Windows.
2. InDesign identifies the new font file as an opentype font file, even though the extension is .ttf and without me changing anything relating to how the font file should be saved.
3. Other font files do not show any characters in the PUA.
Does anyone have an idea what's going on here? Is InDesign actually mapping or mirroring graphics/glyphs to the PUA? (I have also posted this problem in the FontForge forum).
Thanks a lot,