well say i have background color Magenta, CreateMaskFromColor to Magenta also. Smoothing turned off it is jagged and don't look too good. Smoothing turned on and there will be a line with Magenta color around the object. This also happens when using anti-aliasing from drawing programs, but that is understandable since their anti-aliasing isn't meant for having any other background than what is there. It seems to me though that SFML should be able to handle it.