Have you received a call from your offset printer telling you that the fonts you uploaded had a zero file size and (of course) don’t work? What’s up with that?
First of all, this happens only with PostScript fonts. TrueType and OTF fonts are immune. Like just about every commercial offset printer, yours is using an Apple Macintosh.
Mac PostScript fonts contain a “resource fork” which contains the data in the font file. When the fonts are transferred over the internet, they lose the resource fork and arrive with a zero KB font size.
The solution is to compress the font files into a zip file and then transfer the zipped file. When they get to the other end, unzipping them will create an intact font file.