My pixma mp600 stopped printing so I checked the ink cartridges and saw my color ink cartridges were empty. I never print in color!! So I called the company (which wanted to charge me for a question. (I got sales office for free!) and they said that the printer uses color to print black??? So I had to buy three color and one black cartridge at a cost of 65 dollars (yes $65 dollars. Took them home and found out I needed another real small black cartridge. I put new cartridges in and it would not print. I put the old empty black in, and even though there was another black cart in, it still would not print. Not wanting to pay a lot for another cart. I called several refill locations and was told they can not refill pixma mp600 carts!!!. NOW I am so mad I checked internet and found a lot of complaints. I really think we should get a class action suit against Canon for riping us off making us use color cartridges when printing in black. PS: these cartridges are unbelievably small.