Richeson Cotton Canvas Hardboard Art Panels have a soft tooth finish, which makes them the perfect painting surface for oils, alkyds, acrylics, casein and other water-based paints. They are warp-resistant and moisture-resistant because they are mounted on high-density, tempered hardboard (masonite). The hardboard panels are first coated with two layers of high-quality acrylic gesso that acts as an archival barrier between the hardboard and canvas The triple-primed acrylic cotton canvas is then adhered to the already primed hardboard with an archival quality, acid-free glue.