Universal pen for use on overhead film and almost all surfaces Dry safe - can be left uncapped for days without drying up (ISO test 554) Good smudge-proof and waterproof qualities on almost all surfaces Superfine line width approximately 0.4 mm
The Staedtler Pens seem to work more consistently than other similar brands. These Superfine ones are very useful for marking out lines and hole positions on metal and plastic surfaces.