Asphalt cutbacks use petroleum solvents for dissolving asphalt cement. The solvents are variously called distillate, diluents or cutter stock. If the solvent used in making the cutback asphalt is highly volatile, it will quickly escape by evaporation. Solvents of lower volatility evaporate more slowly. On the basis of the relative speed of evaporation, cutback asphalts are divided into three types: rapid curing (RC), medium curing (MC) and slow curing (SC).