Etch Resist Pen, ideal for use on many materials such as silver or plain copper boards when an acid bath technique is to be used with artwork directly printed and drawn on to the PCB. To use the pen, simply press the tip to promote ink flow and apply slow, even pressure in use. This blue etch resist pen is ideal for use on plain copper boards but can be used on almost any surface. Excellent smudge-proof and waterproof qualities Dries in seconds Ideal for left-handed users Permanent, low-odour ink Polypropylene barrel and cap guarantee long service life Can be left uncapped for days without drying up Automatic pressure equalisation prevents pen from leaking on board aircraft Line width approx. 0.6mm Refillable Circuits can be drawn on plain copper laminate and then etched in Ferric Chloride