Yupo paper is a unique alternative to traditional watercolor papers. It's an incredibly durable, stain-resistant, non-absorbent synthetic paper that holds ink and watercolor with razor sharp precision. This extraordinary surface also resists tearing and buckling and it remains perfectly flat. Yupo's ultra white color and super smooth finish makes all of the colors of the rainbow sing when applied to this revolutionary surface. Colors are brilliant and they lift off completely. This synthetic paper made of 100% polypropylene offers a unique alternative to traditional art papers. As a watercolor paper, it has the advantage of being non-absorbent so colors lie on top of its surface producing brilliant vibrant effects. Yupo requires no soaking, stretching or taping flat. Acid free.