4 years ago, without knowing about toners, we bought (Office Depot) a
Canon toner and put inside the HP/3 cartridge... tsk tsk... almost put
fire at the HP/3... then I found a distributor in California who had a
refill toner specially for HP/2 and HP/3, I bought a box with 12 bottles
of 12oz. each for $35 / box.  It worked pretty nice, could refill the
cartridges up to 4 to 5 times before some wearing was visible at the
printouts.  I lost that distributor phone # and never more found a good
offer like that.  Right now starting to look for the LaserJet 5L refill
toner (in bottles, of course).