Tim Holtz Alcohol Ink YUPO is a versatile surface specially suited for watercolor and mixed media techniques using Tim Holtz Alcohol Inks, Mixatives, and Blending Solution. YUPO white heaystock is a smooth, synthetic, ultra-heavyweight 144 lb surface that resists buckling and dries quickly. Non-porous, water resistant surface. Not laser or inkjet compatible. This inch package contains ten 5×7 inch sheets of white heavystock. Adult Use Only Conforms to ASTM D4236. Made in USA.