If I add all of my special fonts from my Mac to the common fonts area, will customers who do not have those fonts installed be able to choose them in the fancy product designer or should I add these to the fonts directory area?
You'll need to add these as extra fonts, only common fonts can be used across all computer and mobile platforms (Arial, Comic Sans,... you can find a list over google).
Okay I added the fonts to my font library but most are still not working when I check my site on my windows laptop. Some of the common fonts are not working either. If it's in font library it doesn't matter the user operating system, right?
Has your issue been resolved, as I can not read any replies from support.