Erasable pens aren't just for kids, they are really quite useful, and if you aren't a pencil person, they can be downright necessary. Even so, erasable pens are relatively uncommon and lots of them are downright bad. The Pilot FriXion erasable pen is the best erasable pen available today.
Pilot FriXion basics
The Pilot FriXion erasable pen comes in two primary styles, the retractable model and then the Point, which has a cap on it. They are essentially the same pen aside from the retractable design. The FriXion is avilable in blue, black, and red, and then comes in fun colors, like dark blue, light blue, green, and purple.
The poplar size of this pen is 0.7mm, but it's available in a slim version that is 0.38mm. This pen, the, Pilot FriXion Ball Slim, actually uses a different design then the standard model. There is also the "Pilot FriXion Color-Pencil-Like Erasable Gel" which is a capped model but is different from the "Point."
Pilot FriXion review
Te Pilot FriXion is far from a perfect pen. The main complaint is that the ink is too light -- in every color -- so that the blues and blacks aren't as saturated as they should be. The FriXion is not that smooth either, even in the 0.7mm size, which is quite generous compared to the 0.4mm and 0.38mm sizes.
But, hey, it's erasable.
Past that, the FriXion is very erasable, by using the rubber tip on the end you can remove almost every remnant of the ink that you put down, so much so that you can write and rewrite on the same area of nothing-fancy notebook paper multiple times. That means not that only does the ink come up but the eraser doesn't rip up the paper either. Part of this has to do with the ink, but also the eraser, which isn't a rough pencil eraser but rather a piece of rubber that just rubs off the ink.
The FriXion is smooth enough to write with for extended periods of time without hand fatigue, but it's nothing close a premium non-eraser gel pen, like the JetStream 101 . Overall, it's much better than it needs to be, and there is no comparison to the terrible EraserMates that many of us smudged our way through school with.
The best pen in the line is the Pilot FriXion Ball Knock (retractable) in black, but the blue is fine as well. If you can't standd retractables than the Pilot FriXion Point is fine too.