China markers for use on glass/metal/china and plastic, for technical tasks or measurement, wax tip marks clearly without damaging the material, marking is water and light-resistant, no need to sharpen tip - pull string to exposed more wax, colour - Black. Versatile wax marks on porous and non-porous surfaces, such as china, ceramics, glass, metal, and plastic without damaging the material underneath. This marker is formulated to resist moisture and fading and is paper-wrapped so it never needs sharpening, Just pull the string and peel down the strip to reveal more marker. Erasable with a damp cloth. This pack contains 12 black markers.