I'm trying to trace an image. It's a black and white picture of a tiger. I want to trace it so that the resulting trace is made up of just the black bits of the original with the rest transparent (so I can put it on a number of different bits of clothing).

The problem is, when I trace with my current settings, some of the white bits are transparent, and some are white shapes on top of the black stuff.

Sorry, my terminology sucks, and I'm a real newb to this, but if anyone can help, it'd be much appreciated.