Slow the drying time of your acrylic paints by using the Matisse Drying Retarder medium.
Additions of MM1 Drying Retarder may be used in watercolouring, water wash effects, stain painting and hard edge techniques where it assists in pigment wetting, rapid colour diffusion and penetration. On raw canvas, the addition of 3-5% MM1 Drying Retarder, pre-diluted with water, will improve the mixing of inorganic pigments, oxides, earth colours, titanium dioxide and metallic pigments.
MM1 Drying Retarder will slow the evaporation of water from the paint. However, excess amounts of MM1 Drying Retarder (over 10%) will severely slow “cross linking” of the acrylic. Therefore, even though the paint may look dry (and indeed all the water will have gone from the paint), it will not have “cross linked” or “cured” so it is able to be re-wet, i.e. with a wet brush or cloth. This allows the Matisse acrylic colours to be used just like watercolours.