Posterman Waterproof Pens are great for external use, they will not be washed off by rain or smudged by little fingers, and they are easily removed with our DuraChalk Cleaner®. They are suitable for non-porous surfaces and great for use on glass, simply outline your text in black when used on glass for a crisp edge. These chalk pen markers will provide bright solid colours and can be overlaid without blurring or bleeding for a striking result. Sold in a pack of 8 pens with 6mm tip, consisting of orange, blue, yellow, brown, green, red and 2 whites.