ONYX resins are available in 2 speeds.ONYX FAST resin has a pot life of 2.5 minutes and a cure time of 10-15 minutes, while ONYX SLOW has a pot life of 5 minutes and a cure time of 90 minutes.Advantages that ONYX resins offer over other resins;1) if you desire a black casting, adding color pigment is not necessary 2) cured plastic is ultra-black and darker than competitive black resins, 3) cured ONYX plastic can be polished and buffed to a high gloss shine and 4) ONYX offers higher heat resistance vs. competitive black resins, 5) unlike other black resins, ONYX does not contain mercury 6) ONYX is less expensive vs. other black resins.Applications include reproducing sculpture, making prototypes and potting / encapsulation. Due to it's quick cure time and hardness, ONYX® FAST is a good choice for creating fast cold cast bronze, brass, copper, nickel/silver, etc. effects.