Markers are ideal for indoor or outside use. The 1”, 2” and 3” series are made from laminated Mylar. Our 3.5” Economy series is unlaminated vinyl. All markers are screen printed and should be durable 2+ years outside (although most labels last much longer outside). Label equipment, inventory, shelving, drums, etc. Order individual letters or numbers or order our handy kits with all of the numbers or letters.