Listo 1620 - Box of 12 - BROWN COLOR - China Markers/Grease Pencils/China Marking Pencils/Wax Pencils Mechanical, Refillable Marking Pencil that writes on any non-porous surfaces, such as metal, acetate, plastic, glass, and even photos. Brown grease pencils are best for marking on transparent and light colored surfaces Wax lead is non hazardous and non-toxic making it safe to use in both industrial and households. Unlike peel-off china markers, these mechanical pencils can be used fully (no wastage) and can write on wet and damp surfaces. Use Listo 162 refills once you finish the grease stick in the pencil. Easy to wipe off with cloth and a tiny bit of window cleaning spray or use a little water and some elbow grease. Used extensively in restaurants to write on packages and plastic glasses; construction industry to mark on tile, wood, metal, concrete etc; households to mark on freezer bags, milk storage bags, general storage boxes and many more uses.