Steve,
Postscript does not *have* to be `ASCII'. That is, it can easily have
characters outside the \040-\176 range we normally use as printable
characters. And I have seen this done in practice with commercial
software. We have WordPerfect installed on some Sun's here and while
it was being installed I got to look at it's postscript output to see
what it looked like. The commands it defines for its own convenience
have names in the \001-\037 range ... something which could screw
up an MTA somewhere, usually on BITNET.
Therefore your assumption of `Postscript is a text format' is what
needs some correction. ;-)
David