Hate to dig the knife in deeper or add fuel to demand for the unavailable... but this knife can be used for digital retouching!
I'd been given an LCD monitor with a stubborn mark across the face. I'd assumed it was a scratch so left it alone and put up with it, not wanting to look a gift horse in the mouth.
Well, thinking there's nothing to lose... I got out this etching knife and went over first a small discreet section of the monitor to get a feel for the texture...
Then I went to the gash mark and completely removed all traces of it from the monitor. Apparently the mark was a "skid mark" from the edge of something else plastic (like maybe a keyboard), and it came right off. The monitor surface is surprisingly "hard".