Put your powder on the paper where the tape will be when it's folded down (see pic.). Now fold the flap down and press on the exposed tape to pick up the powder. Lift the flap to see where the powder wasn't picked up, fold it back over and press in those spots to get an even coating. Take it off and fold a little bit of the powder coated end over and roll it up tightly (the part without powder is to hold it together). Recycle unused powder.
since it doesent seem to show up anywhere, heres a smoke bomb
that this can be used with