Laser printers have become routine office fixtures as their prices have dropped. But the cost of toner cartridges can easily make the printers expensive to use. There's relief. Remanufactured cartridges are available for laser printers made by Canon Inc., of Japan, and for many other printers.

New Canon cartridges -- usually good for 3,000 to 4,000 pages -- sell for $90 to $120 each. If you use no more than three cartridges a year, you should buy new ones, since any savings on remanufactured ones will be small.

Remanufactured cartridges typically sell for $50 to $60 with the exchange of an old cartridge. The best way to find a remanufacturer is through referrals from other laser printer users; also check the back pages of local computer newspapers.

Not all Canon cartridges can be remanufactured easily. The EP cartridges used by early Canon printers (Hewlett-Packard LaserJet, Apple LaserWriter, and others) can usually be rebuilt four to six times without difficulty. But the EP-S cartridges (HP LaserJet II and III, Apple LaserWriter II) and EP-L cartridges (HP IIP and Apple Personal LaserWriter) have softer photoconductor drums good for only one or two recharges. To prolong the life of those cartridges, several companies offer replacement photoconductor drums. A recycled cartridge with a new drum can cost as much as a new cartridge, but it can be refilled six or seven times.

Properly done, toner recharging works well -- so well that Canon discourages the practice by trying to keep old cartridges off the market. Canon offers to ship spent cartridges for free to a recycling center that reportedly grinds them up.

-- Cary Lu