I am cleaning up some sins done in the past, when still doing trial and error type design (wondering if I have advanced from this level until now :)
I have a font that has ascenders as high as 800em, and descenders to -300, which results in an UPM-size larger than 1000, exactly 1100 EM. It is intended to be and drawn as a Opentype font with Postscript outlines, mainly for use in DTP environment (but i'd like it to be compatible with office applications if possible). Fontlab 5 tells me that a UPM-size other than 1000 may cause problems.
I've done a recherche on the web and found out that there are cosmetic problems in CS1-applications (cursor size, ...), but could not find anything "serious" endangering the use of such a font. These postings were relatively old, the newer ones from 2007.
Are there, in 2009, known problems for fonts with this settings? Scaling down to 1000 is quite difficult (ugly or much work), if it is possible without problems, i'd like to stick with the 1100...
If there are problems to be expected: What happens if I set the UPM size to 1000, force the descender to -200, and still have glyphs that reach down to -300? Clipping? Even more dangerous things?
Thanks for your help