With this Arches watercolor paper block you get 300 lb. (640 gsm) Arches Cold pressed watercolor paper with the convenience and portability of a watercolor block. The cold-pressed sheets are 100% cotton, acid-free and buffered with an anti-microbial agent to help resist mildew. The Arches Watercolor 300 lb. Block contains Ten 12"x16" sheets per block.