Hey all, just discovered this forum yesterday while looking for supplements to DMing, and I haven't worked in photoshop or any similar program before, but I have been having a lot of fun with the tutorials around here.

Anyway, I mention that because I am probably doing something silly, but when I follow ascension's guide to continent creation (render clouds, copy, new layer->fill 50% grey, hard mix, then airbrush black for water white for land), as soon as I get to the step where I am airbrushing in the continents, my black brush works beautifully, and I can eliminate the land I don't want, but when I switch to white it has no effect whatsoever, even if I set it so that only the layer I am drawing on is visible.
Any idea why only the black seems to draw, and not the white? Thanks!