Leakage in a scroll wrap compressor is reduced by providing a roughened scroll wrap tip surface at the gap between the tip and the cooperating base so as to increase the frictional resistance to flow of fluid through the gap and to cause turbulence within the gap to further increase the resistance to the flow of fluid from the high pressure to the low pressure side across a scroll wrap tip. Various types of surfaces are shown for increasing the frictional resistance to flow such as knurling, grooving, cast cavities, metal particles and fibers and the like.