The Artline 70 Permanent Marker is ideal for marking a variety of porous and non-porous surfaces including steel, glass, cardboard and wood. It has a bullet tip so you can control your strokes easily. The markers have a bullet nib so you can attain a 1.5 mm line width. They are suitable for a variety of surfaces including cardboard, wood, steel and glass. These markers have round barrels which are comfortable to hold. The ink is designed to be vibrant and stand out from the board. These markers are xylene free for your peace of mind.