Atelier medium Modelling Compound in 4 litres. great value to buy in bulk this way! Modelling compound can be used for building impasto areas in painting either before or during an stage in the painting process. It dries to a white satin finish and remains flexible .Also ideal as a ground prep for canvas,paper or other painting surfaces. May be added to Atelier Acrylics as an economical paint extender. Also available in Impasto Gel paste for exaggerated structure and textural effects.