Ooops - I pressed Post instead of using return!? <: DUH! I was going to add that to alter the fuzziness of a cloud's outline, just mess with the fuzziness control under base density. You can then have totally defined clouds or very wispy clouds with little effort. Beware two things, though - 1) If you overlap volumetric shapes, Bryce throws up giant and nasty artefacts that you'll need to correct in post. 2) For a decent cloud you'll need a quality of 60% plus. The ones above were 75-ish, as I recall, but I think you'll only need to go above 80 if you're going for 300dpi+ hardcopy.