Legendary 1000H 100% cotton sheet made transparent without the use of solvents and features a smooth, transparent, and uniform surface Pen and Pencil lines come out Sharp and clean with no feathery edges or ghosting and is compatible with a wide range of fine art media Paper retains strength, stability and transparency under exposure to heat, light, and atmosphere; and won't become Yellow, brittle, or opaque with age Book is constructed with an innovative patent pending InkBlock panel which is inserted underneath the working sheet to prevent any marking or indentation to the sheet below Made in USA