I have not seen this problem addressed in any forums I have visited in the past. What is up with the quality of priniting via CUPS of photos in Linux? Print quality for text is great but from what I see photo quality sucks. I have a winprinter HP720C for which I should be grateful that it prints at all but is it possible to get a clean photo print job? I see in my prints horizontal lines through out the photo. Eventhough they are faint (I think pink) they are still there. I have the latest CUP update. Is the problem the current state of development of the Linux kernel or is it my printer?

It is almost certainly your printer (this is a winprinter), but there *may* be setup problems.
Have a look at this site for information and instructions:
http://www.linuxprinting.org/show_pr...P-DeskJet_720C

Make sure you clean the printer on a regular basis, and also keep those print cartridges stored in airtight containers when not in use. . .