Beautiful, highly saturated, acid-free, transparent colors for your classroom or art project needs. They are alcohol-based, making them indelible and moisture-resistant when dry. You can work freely on almost any clean surface, including glass, plastic, metal, paper and vinyl. Highly-versatile for a variety of applications: rubber stamping, fine art, wood and leather, faux finishing techniques and airbrush. Set of nine 1/2 ounce (14 ml) bottles. Conforms to ASTM D-4236.