Draw or write on most surfaces including paper, glass, wood, porcelain, plastic, and metal with SAKURA Pen-touch opaque paint markers. Industrial applications include marking and identifying parts, pipes and tubing, sheet metal, wiring, construction assembly, manufacturing and fabrication processes. Shake with the cap on before writing to get the paint flowing and mix the color. Before use, depress tip in upright position to release any internal pressure. The paint flows from the chamber directly to the tip of the marker.