Mixture of water and propanediol with acrylic polymer. higher viscosity version of the Retarder which added to acrylics extends drying for a very long time, up to three times as long as the regular Retarder.
Lascaux Retarder Ultra will change the viscosity of Lascaux Artist Acrylics only slightly. Adding Lascaux Retarder extends the relatively short drying time of acrylic colours on nonporous supports and keeps paint film open longer: up to a couple of hours. Lascaux Retardern Ultra reduces the evaporation rate of the water and enhances the reemulsifying capacity of the paint, i.e. dry paint film. The addition of Lascaux Ultra Retarder does not alter the hue of the colour.
Lascaux Retarder Ultra will keep indefinitely. However, it should not be exposed to direct sunlight as this may lead to a slight darkening of the product. Lascaux Retarder is generally regarded as physiologi-cally and toxicologically safe in conventional usage. USA: conforms to ASTM D-4236.