Another source of unscented talc can be found by buying several “
Soapstone " marking sticks from any welding supply shop. Ask for
soapstone for marking steel for cuting . It comes in two sizes, 1/4"
rounds by 5” long and 1/8 " X 1/2 by 5 " long. Rub them on fine
emmery cloth or a file to make a powder. These soapstone items are
also very resistant to acids and bases and moderate heat. Laboratory
tables were made from them. ROBB.