Chromantics Giant Coloring Posters work Great with both Crayons and Markers. At 30 in x 40 in, Our posters are large enough for an afternoon of fun or even a coloring party! All of Chromantics Coloring posters are made with ultra smooth Thick Matte paper perfect for a variety of dry media including crayons and washable markers. All of Our posters are designed and illustrated by artists in California and are manufactured in the USA. For best results keep Chromantics coloring posters away from any moisture. We do not recommend using wet media, such as watercolor or paint with these posters. Once all colored in these posters make great decorations!