o use the dichromate for gum printing, the raw crystals need to be dissolved into water making an Ammonium Dichromate solution, ready for printing. I mix and store mine in an 8 oz. cheap plastic shampoo bottle from Wal-Mart. (however these travel sized bottles may prove difficult to find as I got mine in 2003 before the airport liquid container problems), I mark the bottle with a clear skull and crossbones and keep it out of reach of any curious children. Be sure to treat the chemical responsibly. Also remember that it is reactive to heat. If you happen to live in 105F degree summers like me here in Texas, certainly do not store it in your garage