3 mm. Bold to the max and permanent to the core, Sharpie Permanent Markers inspire you to transform ordinary surfaces into passionately creative statements. The permanent marker with a split personality, Sharpie Chisel Tip Permanent Markers have a versatile tip that makes both broad and fine strokes--so you can express yourself any way you want. MARKER,SHARPIE,CHSL,BE Marker Ink Type: Permanent; Marker Tip Type: Chisel; Marker Tip Size text: Medium; Marker Tip Size numeric: 5.