Now and then, I like to print multiple copies of something. Like, 90 copies at a time. This should be a snap, but some combination of my old HP LaserJet 4000 and CUPS prevents it working. Doesn't matter how nicely I ask, I always get 1 copy, no more, no less. Finally found the answer:
lp -n 90 -o Collate=True -d HPLaserJet my_file.ps
Just one more thing to keep me banging my head against the desk!