One thing to keep in mind is that the bran adds bulk and thickness. As an experiment, we prepared one paste using both rice bran and glutinous rice flour, and another paste using just glutinous rice flour. As it turned out, both made good resists – but the glutinous rice flour paste did not come out as thick and dried to a much thinner layer as the paste with the bran. This is because, on its own, the glutinous rice flour paste absorbed more water during steaming than the mix of glutinous rice flour and bran. The “pure” rice flour paste was also significantly gummier and (in the bowl) lacked the crisp definition of the mix of flour and bran. It still made a good resist for the stencil used, but I wonder whether it would be too runny for a stencil with lots of fine details. More experiments needed!