100% Cotton papercotton. Traditionally made on a cylinder mould Acid- and Chlorine-Free, pH-neutral, and Archival 300 Grams - 140 LB Available in Cold Pressed, Hot pressed and Rough Natural Gelatine Sizing to the core of the paper Natural White with no optical bleaches Watermarked sheets Block contains 20 sheets Blocks are glued on all four sides [Friendly tips] Do not use your fingers to touch the paper, the grease on your fingers will react with the pigment, and the pigment will not adhere to the surface of the paper! The interior and exterior are made of traditional gelatin and are available in hot press, cold press and rough texture This product is an Academy grade, essential painting paper for beginners, it is acid-free, pH neutral, contains gelatin internally, chlorine free and air dried, if you want to try the next level, you can choose our artist grade, Artist Watercolor paper is more suitable for master painting.