I have the above printer. Do not use it a whole lot but on occasion. I was wondering if the cartridges themselves have an "in use" life and should be discarded after a certain period of time in the machine whether they work or are empty or not. I originally just left them in until no longer worked but I think I recall reading somewhere that they should be discarded a certain length of time after opening but have forgotten where I saw this and was wondering what the general feeling or knowledge is about this. If I put them in the machine a certain date then should I discard them on a certain date afterward?? Thanks for any input, suggestions, or advice.