Create cool effects on dark paper, poster board, plastic, foil, glass, and more. Crayola Gel Markers are designed for coloring that stands out on smooth surfaces, giving young art students lots of creative options to interpret their school projects. Gel Markers are made of recycled plastic and solar energy - a good subject for science class as well as art lessons. They're also non-toxic and washable, making them safe for children and practical for teachers. Each pack includes 8 washable markers.