OPEN Thinner is a water-based additive for thinning the consistency of OPEN Acrylic Colors and Mediums without altering drying time. It also maintains and adjusts the workability of OPEN colors on palettes and can be used as a thin-bodied retarder with Heavy Body or Fluid Acrylic colors. Because OPEN Thinner contains no binders, it does not form a film and should only be 25% or less of mixtures with acrylic colors and mediums (one part OPEN Thinner to three or more parts paint or meduim)