Microcrystalline is a relatively new petroleum-based wax, which will give off vapors in the molten stage. Extra consideration should be taken to provide proper ventilation. Microcrystalline has a higher melting temperature than beeswax so it is more pliable allowing for more time to mold, shape, model, cast, carve and form objects. Microcrystalline is also less expensive than beeswax. Microcrystalline wax will yellow over time from exposure to UV so it is very important to paint over and encapsulate the impasto wax layer.