The Fluid Hot Press 140 lb (300 gsm) Easy-Block contains 15 sheets of acid-free, archival watercolor paper bound on two sides. High quality at an affordable price, Fluid Watercolor Paper is crafted in a European mill which produced its first paper stock in 1618. Mill masters craft small batches at slow speeds allowing for finer control of quality. This slow approach produces a sheet of great strength that shares much of the working integrity of more expensive mold-made papers. Paint directly on the top sheet in the block. The glue along the two long edges will hold the sheet flat as you paint. When your painting is dry, slide a dull knife or letter opener in the open side under the top sheet. Release the glue along one edge and pull your painting free. ISO 9706 Compliant Permanent Paper.