From the Manufacturer:
More durable than canvas, wood panels resist flexing or warping, making them great for painting, especially thick, heavy applications and palette knife work, as well as encaustic, mixed media and craft use as a shadow box, frame or tray. The 4mm hand-sanded birch wood surface is smooth for detailed work and mounting. The sturdy pine cradle adds support and allows for hanging without a frame. Gallery depth panels have a 1-1/2" deep profile.