It's a poster, it's a placemat, it's both. Smart Poly® material has been designed for the classroom and home. The material is strong, durable, water resistant, and does not need lamination. Heavy duty surface for fun and colorful learnings. Write-on/wipe-off surface for use with dry erase or water based markers and washable crayons. Measures 12" x 17.25" . Learn about Dinosaurs and the time periods in which they lived.