The T0549 offers another level of depth to images. This is because it gives another set of various colours that can only be derived from the dark blue ink it offers. It offers another extra set of colours, hues, and tints to give essentially another dimension of colour into the usual coloured photos that we see. Therefore each image seems more realistic and vivid now, because they can mimic real life better. You can use this cartridge for both home and work use, and wherever you think it seems appropriate to have well defined photographs. The 20ml dark blue cartridge is compatible with the Epson Stylus Photo R800 and the Epson Stylus Photo R1800.