Staedtler's permanent marker pen for the garden is a new and practical development from the Lumocolor range. As a garden marker it is also waterproof and light fast, so you'll never need worry about your plant labels fading. In addition to marking labels, the permanent garden marker can be used for signs, flowerpots or anything your green fingers desire. Medium Line, 1.0mm. Ink, Black Permanent Ink. Purchasing each unit.