Many prewritten filter packages (and other printer-related software)
are available from
Metalab. Such
utilities as psutils, a2ps, mpage, dvitodvi, flpr, etc can all be
found there.
For a while, there were several packages out there all trying to make printer configuration easier. They probably all still exist, but one of the best and most up-to-date is Andreas Klemm's APS Filter package, which has a menu-driven printcap configurator and handles practically any type of input imaginable. If your vendor doesn't ship a nice printer setup tool, APS Filter is the way to go.