Mad Cook
Master Chef
IIRC you can't refill HP cartridges as they have a chip in them.Himself has resorted to refilling them himself (not too sloppy, or else he's very neat) and also ordering the replacements by mail. You send them empty ones in a self-mailer, they send full ones back. The company he has used is Printpal :: Discount Printer Ink Cartridges, Toners & DVD SuperStore. If you do "/coupons" at the end of the address you might be able to get an additional 10% off.
When I was the "stationery monitor" at the utility company I had to order proper HP cartridges for the managers who had HP printers but Canon, Epson and Lexmark printers would accept "look-alike" ones. It annoyed the hell out of me because it fouled up my financial stats.