The shell of the art storage book is made of environmentally friendly PP material, with strong flexibility and no peculiar smell. Children can also rest assured to use it. The inner pages are made of PP material, soft material, high transparency, waterproof and wear-resistant, transparent and non-reflective. Vertical openings are easy to extract. Adopt ultrasonic welding process, durable and not easy to fall off. Rounded edges don't hurt your hands.