DescriptionArches® Watercolor blocks are 100% cotton paper of the highest quality and glued on all 4 sides. This French made paper is manufactured on a cylinder mould, just as it has been made for more than a hundred years. The convenience of working on a block provides support, durability, and eliminates stretching. Acid-free and gelatin sized.Superior quality, mold-made paper from the Arjomari Mills of France. Made from 100% rag, these 140 lb. blocks provide a convenient assortment of sizes, weights and surfaces that are ideal for field work. Twenty sheets per block.