Permanent marker (round core) that produces vivid color even when writing on metal, glass, or black paper. Opaque ink writes vividly on black objects Ink color: blue; Fine line; Line width: 0.03 - 0.05 inches (0.8 - 1.2 mm); Ink: Opaque, oil-based ; Material: Shaft: Aluminum; Pen core: Sliver (acrylic); Product size: Painters shop Dot Com Postcard A; Limited product!! 1 x Cute Animal Postcard