This is a fantastic quality glasochrom / chinagraph pencil perfect for use on our 140mm plastic plant labels. This pencil writes waterproof and is U.V. stable. We have used this pencil in our nursery for years without ever having a pot or tray of plants without a readable label.
This pencil can also be use on materials like paper, plastic, metal, glass, wood, leather and stone. It is also safe and suitable to use on materials which are completely submerged in water.