Carding comb works great. Just remember that there are two types; one
for cotton and one for "all others." Just look for a store that sells
spinning and weaving supplies. Tell them you need a set of carding
combs for silk (the ones that will do cotton are too coarse). They'll
hook you up.
The problem with the blender method is that it doesn't do long fibres
well. The carding combs do them and then some. No, its not automatic
like the coffee grinder, but I get a good color match using the carding
combs as I can add bits of color and see rather quickly how it comes
out and if I need to adjust.
Frank Reid