Mont Marte Acrylic Retarter Gel slows down acrylic paint normal drying time. Practice usage before committing to your final artwork.FEATURESdelayed drying time facilitates easier blending of colours and enables a smoother coat over larger areasthis medium may change its viscosity drying times may vary re: quantity used and environment. TIPSsuggested mix ratio is 1 part medium to 4 parts paint – experiment for varying results. Drying times may vary re quantity used and environment. Practice usage before committing to your final artwork.