Mark dusty or oily surfaces, concrete and brick with Empire Multi-Coloured Permanent Markers. This Pack includes eight Markers (black, red, blue, green, yellow, orange, brown and purple) to label different materials. These Markers apply permanent ink that’s water-resistant and non-toxic. The ink is also fast-drying to reduce smears and smudging. With their caps removed, these Markers will still work for up to 72 hours. The durable acrylic tip resists wear on rough surfaces. Use the anti-clog feature to remove contaminants from the tip and prolong performance. Just tap the marker pen on the edge of another surface to remove debris such as dirt and sawdust.