Arches watercolor pads contain paper made with natural cotton fibers on a cylinder-mold machine. This artist-grade watercolor paper is great for watercolor, gouache, acrylic, and airbrushing. Arches is made with a natural gelatin sizing. These pads contain 12 sheets of natural white, acid free, and 100percent cotton paper in a fold over pad. This pad is 9″X12″ rough 140lb/300G.