The Round Wooden Art Panels front and back are made of natural maple hardwood veneer. This painting surface has no knots, seams or voids. The 5 layer balanced construction prevents movement, and the waterproof glue keeps each layer from expanding or contracting. Art Boards™ Round painting panels are incredibly stabile and perfect for all painting mediums including traditional egg tempera, encaustics, oils, acrylics, and more. All round art panels are sanded and ready for Gesso.