I particularly like the red pen for proofreading on paper. I prefer pen over pencil for proofreading because it shows up better and is clear and sharp for making small marks. The problem has always been trying to keep things tidy when I can’t erase my marks. I was very fond of the Bic Wite-Out correction tape for covering up mistakes, but erasing them is far better.
So far I’ve tried the blue 0.7 mm Frixion Ball and the red 0.5 mm Frixion Point, and I like them both. The colour of the ink is nice, and they use a gel ink that isn’t greasy and doesn’t run or smudge. I don’t know whether anyone has had a problem with the ink fading under hot conditions (like a car dashboard in the sun), or whether the erased marks can be made to show again, but I haven’t noticed any problems with durability.