Stillman & Birn Zeta Series - Wirebound Sketchbook - Portrait 9 x 12 - 270gsm White PaperEXTRA HEAVYWEIGHT PAPER: Stands up to advanced wet media techniques. Great for detailed pen & ink line work combined with liberal applications of watercolor. A favorite of botanical artists and illustrators. CRAFTED FOR MIXED MEDIA: Double sized (from non animal materials) for enhanced wet strength and glowing color. ERASABLE & TOUGH: Accepts multiple erasures of dry media and lifting of wet media. DURABLE: Thick board, premium U. S. coil wire binding