Heat Resistant Mylar Template Plastic 12in x 18in creates a sharp, flat edge for perfect hand appliques without melting the template. Heat resistant Mylar is an excellent work surface for modeling clay, paint and hot glue guns. Iron glides over Heat Resistant Mylar without damage to template plastic or iron. Withstands heat up to 450 degrees. Template is a clear plastic. It's pictured as gray so it's easier to view on the website.