Pilot FriXion Ball pens belong to the large selection of gel pens from Pilot, using the new, clever Metamocolor technology, or what the chemists at Pilot Pens call, thermo-sensitive gel ink formula, which turns transparent when friction is applied to it. A small rubber on its tail serves as an "eraser", and the ink disappears neatly as no eraser dust is produced in the process. Pilot claims that this "erasing" process does not pose any damage to almost all types of paper at all. Because the ink in these pens is easily erased, they cannot be used on legal documents or on any other official papers. The ink on these pens turn colorless when exposed to extreme temperatures (<14°f;>140°F). Their color can be restored, though fading, when placed in freezer to cool.
For practical and obvious reasons, I won't use these FriXions to write on my Moleskine, though. That notebook is reserved for my Pilot G2s. But these FriXions are great, cool pens! Especially when you're around people who get impressed with the idea of erasable gel pen inks. *Wink.*
Yeah, cool. Cool pens, these FriXions are. They're very handy when doing crossword puzzles, or Sudoku. Want more cool stuff about these pens? Watch this promotional video released in the US. Now this is one cool video for one cool pen.