I have bought these for a few years but I have had increasing problems with my canon printer recognising them and then the printer refused to accept either. I returned them to Tesco Heswall with a reference number obtained from, I thought, Tesco because I couldn't find the receipt and didn't have the packaging. I was told very firmly that an exchange couldn't be made and when i insisted the member of staff, with very bad grace, went to seek advice. On return she replaced one xl cartridge with the same but I didn't notice that the other xl cartridge was replaced with a smaller one. I requested a receipt but was told that i couldn't have one. That followed with the alarms sounding as I left the building. I stopped, and complained to the security guard that I was fed up with being treated like a thief. the guard said that he had seen me at customer services and allowed me through. Now one will work and the black is not working. I am fed up with purchasing unusable items- to some extend this problem has to some extent probably been part of the last 4 purchases. A lot of money to pay out for faulty goods and bad staff attitudes. User's recommendation: Don't buy Tesco replacement cartridges.