So this is my take on creating a "smoke" brush in Illustrator, spelling out (what else?) SMOKE! The process was fairly simple, although for some reason I had to redraw my original "plume", because when I tried to apply the Envelope Distort, it was not creating a smoky effect, just blended lines within the plume shape. Don't know what was going on there, but when I deleted and created a new shape, it worked fine. This could be fun within an illustration; I'd like to try making some shapes or drawings with it.