OPEN Thinner is a water-based additive designed to thin the consistency of OPEN Acrylics without altering open time, as well as maintain and adjust the workability of colors on the palette. It can also function as a thin-bodied retarder when used with heavy body or fluid acrylics. It contains no binders, does not form a film and should never be used alone. Details:Available in multiple sizes,Water basedSoap and water clean up