RENDR Lay-Flat Sketchbooks feature a unique lay-flat binding designed so there is no bump in the middle of the page, and no need to hold the book flat. Draw on both sheets to create one large drawing. Create on every page of RENDR's revolutionary bleed proof paper front and back and with any type of media including but not limited to solvent-based markers and acrylic washes. RENDR is acid-free, lignin-free, 110 lb. (180 gsm) paper, tape-bound, each sketch book contains 32 sheets (64 pages).