A release agent is required when stamping concrete. Without it, the concrete paste can adhere to the stamp, ruining the final texture and appearance. There are two primary kinds of release agent: powdered and liquid. Powdered release agents will become embedded in the low stops of the concrete (the high spots of the stamp), imparting a contrasting color in a process called antiquing. When the dust of a powdered release is not desirable or antiquing is not the desired effect, liquid release agent can be sprayed on to the surface and the stamps to achieve the same bond breaking effect.