Abstract: This invention relates to a water based aluminum paint, particularly for dark colored polyethylene film for outdoor agricultural uses. This paint has high reflectivity towards light, and is water and crack resistant. It contains aluminum paste or powder, mica as an extender, acrylic polymer, and water, together with a small quantity of a dispersant and antifoam. The acrylic polymer may be modified by the addition of minor amounts of alkyd resins, vinylacrylic copolymer, polyesters, and the like.