What this really boils down to is that printer manufacturers seem to expect to get their cake and eat it. If they sold printers for a price which gave them a sensible return and then sold ink cartridges for similar prices to those at which other manufacturers can provide them then they wouldn't have to make up excuses as to why only their replacement cartridges should be used. Furthrmore there would then be no neeed for them to develop more and yet more sophistaced devices to prevent users from using alternative cartridges. I appreciate tht H.P are a special case because their cartridges also contain the print head mechanism. This is because they were the first to market an ink jet device and their ink jet mechanisms would not last the life of the printer itself. It took a short time for this technology to improve this life to that of the printer itself but HP have steadfastly refused to incorporate this technology and thus all HP cartridges still contain the (expensive) print head. The only reason for this is to maximise their profits from replacement cartridge supply.
P.P.