Skia is a Mac OS X TTF system font mentioned on Usenet by a user who was wondering why the 10 styles available in Apple software would not show in other programs, such as Adobe InDesign.
Intriguing. I decided to investigate, and am even more intrigued now. I made a copy of the font and was able to open it easily in Fontographer Mac or Fontlab Windows. Now, here comes the mystery : both programs can see only the basic font.
FontBook and Apple programs see 10 styles out of Skia Regular (see graphic) which are apparently not mechanical extrapolations but separate designs. Could not figure where they are hidden. The skia.ttf file is 476 k, which seems to indicate some kind of font archive.
More interesting yet, although it is a TrueType font according to Mac OS X, it is considered as invalid when I try to install it or view it under Windows 7.
Apple can be familiar with undocumented system features, but it is the first time I see that in a font. Actually, I would love to understand how they did this : it shows that somehow, they indeed created an anti-copy system of sorts. How could one copy a font file that does not show ?
Thank you in advance for all information about that mystery. If this is the result of my own ignorance, please enlighten me. Recognizing one's limits is the beginning of wisdom...