The SlapItUp™ Static Cling 18" x 24" Graph Sheets are statically charged polypropylene that is repositionable, rechargeable, and recyclable. Designed for erasable markers, this material is bleed resistant and cleans easily with an eraser or soft cloth. The sheets can be repositioned or kept in place for up to 6 months. This amazing product sticks to any indoor, dry, clean surface once you've peeled the backer off slowly. If the static charged is lost, simply recharge the product by rubbing it with a wool cloth. Whether your at home or in the office, SlapItUp™ graph sheets are great for brainstorming, presentations, school projects and more!