According to the Adobe technical note #5135 titled "Supporting PostScript Fax", the PostScript interpreter handles an incoming PostScript Fax document in the same manner as any other PostScript language document. Depending on how each vendor implements their driver, a font substitution to Courier could take place, or the requested font could be included with the data stream. The LaserWriter 8f driver from Apple assumes that the receiving printer contains at least the minimum 35 font set that Adobe requires for PostScript Fax printers and all other type 1 and TrueType fonts contained in the document are downloaded to the receiving PostScript fax printer with the data stream. These are the fonts that PostScript assumes are available in ROM:
Times-Roman
Times-Bold
Times-Italic
Times-BoldItalic
Courier
Courier-Bold
Courier-Oblique
Courier-BoldOblique
Palatino-Roman
Palatino-Bold
Palatino-Italic
Palatino-BoldItalic
ITC Bookman-Light
ITC-Bookman-Demi
ITC-Bookman-LightItalic
ITC Bookman-DemiItalic
Helvetica
Helvetica-Bold
Helvetica-Oblique
Helvetica-BoldOblique
ITC Avante Garde-Light
ITC Avante Garde-Demi
ITC Avante Garde-BookOblique
ITC Avante Garde-Oblique
New Century Schoolbook-Roman
New Century Schoolbook-Bold
New Century Schoolbook-Italic
New Century Schoolbook-BoldItalic
Hevetica-Narrow
Helvetica-Narrow-Bold
Helvetica-Narrow-Oblique
Helvetica-Narrow-BoldOblique
ITC Zapf Chancery-MediumItalic
ITC Zapf Dingbats
Symbols Set
Downloading the fonts to the receiving printer do add transmission time, but
due to PostScript Level II's built-in LZW compression and decompression
algorithms this averages out to about 35 seconds per font.
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