Smart Poly material has been designed for charts in the classroom and home. The charts are strong, durable, water proof, and do not need lamination. Use with Ashley Smart Tak , pins, tacks, staples, etc. to hang in the classroom. The write-on/wipe-off surface is designed for dry erase or water based markers and washable crayons. Smart Poly Chart measures 13" x 19" with a heavy duty, glossy surface, . 45mm.