Staedtler Lumocolor Permanent Pen 317-9 Medium 1.0mm Line- Black (Pack of 10) Universal pen for use on almost all surfaces Suitable for overhead projection, Also suitable for use on CDs/DVDs Dries in seconds, therefore ideal for left handed users Permanent, low odour ink DRY SAFE; can be left uncapped for days without drying up (Standard atmosphere according to ISO 554)