OK; won't tell, but someone requested a picture procedure (yup; hate doing these; lol). OK, below's the steps.
Start with your target (taken from one of
these brushes):
Export the finished result in a lossless format (I like PNG if I don't port the result as a PSD file):
In GIMP, duplicate the result setting the Top layer to Darken and also add an Alpha channel to this layer (important step; forgot to add that in my original steps) and run Color to alpha using black as the transparent color on the base layer:
Now duplicate the base layer until you are satisfied with it's solidification; note that Threshold Alpha won't give you the same result so this is they way to do this unfortunately. I know I mentioned 5 or 6 dups, but for the feathers, it took around 15 dups; lol:
Done; below's the PNG w/ transparency result. You can then do alpha to selection and invert the selection and grow to cut out the black outline and paste it back and blur for additional drop shadow (do this quite often) but that's outside the extract from black canvas step.
Images hosted free thanks to
ImageShack.