Amazon.com: Fluid 100 Artist Watercolor Block, 140 lb (300 GSM) 100% Cotton Cold Press Pad for Watercolor Painting and Wet Media w/Easy Block Binding, 6 x 8 inches, 15 Sheets
Arches Cold Press Watercolor Blocks – Case for Making
Amazon.com: Fluid Artist Watercolor Block, 140 lb (300 GSM) Cold Press Paper Pad for Watercolor Painting and Wet Media with Easy Block Binding, 6 x 6 inches, 15 White Sheets