Or if you mean that when you print a borderless image it doesn't print on the last couple of cm?
Then it is because of the way your printer detects the paper. It thinks it's got to the edge of the paper before it really has. The only answer to that is to tape an extra few cm of paper onto the end of the sheet you are printing on. If you are printing on photographic paper with a glossy back the strip will peel off once you've finished with it, but if the paper has a matt back you will need to cut the strip off and leave the tape on.