These bold, long lasting permanent markers feature an acid-free in that is great for glass, metal, foil, plastics, photos, coated papers and even oily and damp surfaces. These permanent markers come in a variety of colors and color combination packs and features ultra comfy rubber grips for comfort and control. This package contains four chisel tipped Markers: black, blue, green and red. Contents conform to ASTM D4236. Made in USA.