I have just begun experimenting with sizing papers with gelatin. Upon drying, I see minute sparkly things embedded in the gelatin, which show through in the final prints (cyanotype and Van Dyke Brown). The sparkly stuff shows through clearly and seem to act as a resist to the sensitizer coating.

Anyone know what these things are made of? Can they be filtered out somewhere down the process of preparing the gelatin?

I am using an experimental dilution of 1 packet Knox gelatin (7 g.) to 500ml distilled water. I find that the dilution is viscuous enough for sizing, but not so thick that the gelatin sets in the container.

Any information will be helpful.