(1) Take a light stone and gently slide it over the sweater like water skiing to get rid of a wool ball at once. (2)The sponge used for washing dishes, preferably with a new, cleaner and harder one, will be raised against the sweater and just have to gently slide over it. (3) You can use transparent glue, and is the kind of wide sticky good. (4) I heard that there is a hair ball trimmer on the market can effectively remove the surface of the clothing hair ball, so that clothing lint is not damaged, clothing long as new (but this small used, you can try Oh!)