#1 Pottery Plaster is the standard for making molds, sculptures or bats. Hydrocal White & Hydrastone are good for sculpture, Hydrastone is suitable for outdoors. Always mix plaster into water. Sets in 20-30 min. Use the plaster mixing ratio, below. 100 lbs #1 plaster: 70 lbs. water 100 lbs Hydracal White: 45 lbs. water 100 lbs Hydrastone: 32 lbs. water plaster 50 pounds plaster50$18.00 50 pounds hydrocal50$22.00 50 pounds hydrastone50$26.00 100 pounds plaster100$33.00 100 pounds hydrocal100$42.00 100 pounds hydrastone100$50.00 500 pounds 1plaster-500$140.00