Hero Arts 4"" x 6"" clear stamp sets offer the best quality in the market. They are made in the USA from genuine photopolymer, which is non-toxic, biodegradable, and beautifully transfers ink to paper for a true impression every time. Peel the stamp from its backing and stick to an acrylic block for easy positioning. Mix and match the designs. Cleans up easily with water or stamp cleaner.