I looked through the tutorials, and I couldn't find the answer to this question.

So I was just playing around in Photoshop and trying to create brushes. I made a "blob" shape, and then defined it as a brush. I tested it out on a picture, and for some reason, the brush was showing up as semi-transparent. I had put the brush on a new layer, with fill and opacity both set at 100%, and the opacity and flow of the brush was at 100%, and mode at Normal.

Anybody know why? TIA. :)