That PowerTank ballpoint pen from uni was amazing! (see photo of the process below). It worked on my completely wet, salty paper like a brush! I loved it so much that I even tried to take it with me scuba diving - but at 70 feet it refused to pump ink :( too bad - it would have been a great tool! But it survived the submersion and depth and my vigorous attempts to use it and still works fine on the surface.
