I've read several threads on centering images on the 4900 and haven't found anything exactly like my situation. I never have a problem with sheets, but am starting to use roll paper now. For example, I just want to make a 10x15 print on 17 inch roll paper with a custom size of 17x12 specified. If I just specify roll paper alone in the driver, the printer generously gives me extra top and bottom margins. I have to trim every sheet to come up with a 10x15 print on 17x12 inch paper. If I use a borderless option…retain size…the driver lets me specify "single cut" in the roll paper options and that makes the cut sheet just 17x12, which is what I want instead of something like 17x13.25. Hooray! Oops. Celebrated too soon. Now the image has moved over about 1/8 inch to the left so it is now not centered. Is there a way I can trick this printer into centering an image on the paper size I specify when using roll paper? Thanks!