With its translucent finish, Yupo Watercolour Paper is waterproof, stain-resistant, incredibly strong and durable. This extraordinary non-absorbent surface resists tearing and buckling and remains perfectly flat, eliminating the need for soaking, stretc.hing or taping. Yupo paper allows artists to create shapes, patterns and nuances that are impossible to achieve on conventional paper. The future of paper. Technical specifications: acid-free, 100% polypropylene, 153 gsm, pH neutral.