Dapro 420 Elementis Plasticizer Architectural / Decorative Emulsifiable in water DAPRO® 420 is a liquid additive. The product prolongs the open time, herewith reducing the cracking of emulsion paints. APPLICATION AND PROPERTIES DAPRO® 420 can be used in plasters or high build wall paints. It gives the plaster a pliable structure and prevents cracking during application, due to its plasticising effect. The plaster will be easier to process. In high build wall paints DAPRO® 420 functions as an open time improver, giving the painter a prolonged period to brush the paint and adjust the paint layer.The fact that DAPRO® 420 is a liquid makes it very easy dosable to all kinds of systems.