These Stanley standard, black, Fine Tip Permanent Markers are ideal for electricians, plumber, and general contractors. The ink is quick drying and is ideal for avoiding smudged lines. They can be used for marking copper roofing material, gas pipe, black pipe, wood, and metal, and marking tools and equipment. These markers can be used to colour nuts and bolts which need to be black. Specifications Pack Quantity 2. Colour Black.