Thanks for info & links. Does compatible ink have same depth of colour,vibrancy & longevity as original? I really cant complain about the quality of my Canon prints but I do seem to get through cartridges quite quickly,not to mention the cost of paper.
Looking at various prices it seems that an online print will cost from about 7p for a postcard size print.Equivalent to £2.52 for 36. Not too bad!