Featuring Fredrix's patent-pending Nature Core technology, the base of these archival boards is made from a blend of 100% biodegradable vegetable-based and recycled components. The 3/4" depth is comprised of an eco-friendly, vegetable based bio-plastic, similar in texture to the foam in foam board. This bio-plastic is sandwiched between two layers of 100% recycled, pH neutral chipboard, then the board is mounted with pre-primed cotton canvas, ready for painting! Since they are so lightweight, Nature Core boards are perfect for plein air painting, and as with all Fredrix canvas, they are archival and designed to last a lifetime. Ensure the longevity of both your art and the planet with eco-friendly Nature Core Paint Boards!