Fun experiments with Pilot FriXion ink

I have been really enjoying the Pilot FriXion 4-colour pen to make notes and graphs. The pen not only has a 0.5mm fine tip in 4 colours, but the FriXion also allows “erasing” the text by friction.

This is not happening by abrasion like pencils are erased, but by heating up the ink.

Wrote the text
Erased the E and A (note that the camera is a lot better at seeing the “erased” text than the naked eye is, in person this seems erased)

I read in a review of the pen that someone left the pen in the sun in the car and now the ink was blank as one would expect. But there was a response suggesting leaving the pen in the freezer “to restore the ink” which was surprising.
So I thought about trying it out and put the paper in the freezer and lo and behold it indeed came back:

After a night in the freezer

In the Ophan X book “Out of the Dark” (by Gregg Hurwitz) the bad guy makes his notes with a FriXion pen and “destroys” these by using a microwave. As in the story, a part stays legible, just like my attempt:

“Erasing” by putting the paper in the microwave.

However, besides just increasing the contrast like my phone does, all Orphan X had to do was put it in the freezer and…

And recovery with ten minutes in the freezer.

More on the background of the chemistry can be found for example here.

Fun stuff.