I am very pleased with these cartridges, very good print, never problems that the printer refuses to cartridges. For 6 star. The only downside is the amount of ink. According to the manufacturer 25ml for Black (PGI 550 Bk) and 15 ml for the other. That is not the facts !!. The full cartridge (yellow, magenta, etc.) predominates 25 g, the empty cartridge 17 g. (Empty means that the printer has "empty" and reported without cartridge change not printed). This means 8 ml usable ink volume - and not 15 ml could favor the manufacturer. argue: Yes, but as a sponge in it and holding back the waste ink. Even that does not correspond to the facts. The Sponge actually restrains ink, but not as much. I wanted to know more and have the sponge removed (there are 2 sponges superimposed) then the cartridge filled to overflowing with water, Capacity 14.5 ml (if no sponge would be there !!), so be careful never 15ml Ink in the cartridges. Even if it would be dishonest to speak of 15 ml when the usable volume 8 ml are.
Actually that is not soo important because the cartridges are priced nevertheless extremely cheap and I will buy again and again. Problems can only asking to be scheduled with the specified amount of ink and suddenly stands there without ink.