Flocking Flock

I'm trying to make some modelling flock, with only limited success.This is made from bits of a kitchen sponge, whizzed up in a blender, coloured with ordinary house paint kneaded through, dried in the oven and then ground again in a little electric coffee grinder.It's not utterly worthless, but I was hoping for a smaller grain size than this. Also, the sponge is yellow, so that affects the final colour.As it is, this is really no better than the sawdust flock I made some years ago. In fact, it's probably a bit coarser.I'll give it another go with some white open-cell upholstery foam, which should colour more accurately, and will hopefully grind down to fluffier bits.