Write on chalkboards, windows and more with this pack of liquid chalk marker pens. This pack contains 8 brightly coloured chalk markers, each marker pen has a chisel tip and writes on and wipes off easily. These chalk markers can be used on most non-porous surfaces including glass, plastic and metal.. uni Liquid Chalk Marker. Pack of 8. Colour - Red, Yellow, Blue, Pink, Green, Orange, Purple and White . Rain resistant. Nib width - approx. 8.0mm. Ideal for small businesses, pubs, cafes and schools