- Matte black, 100% cellulose paper for opaque mediums - Artist grade, 140 lb (300 gsm), cold press sheets - Glued on all four sides to prevent buckling and warping - Each pad contains 15 sheets of acid-free paper - Works well with metallic watercolors, acrylics, gel pens, pastels, and more Van Gogh Watercolor Blocks allow you to achieve stunning contrast and create vibrantly colored art. Metallic watercolors, gouache, and colored gel pens pop against the rich black, 100% cellulose sheets, and the cold press texture is perfect for sketching or painting delicate details. Dry mediums such as charcoal, pastel, and pencil perform beautifully on the finely grained surface, as well. Glued on all four sides to prevent buckling under large washes and layered techniques, each block contains 15 sheets of 140 lb (300 gsm) acid-free watercolor paper.