Dspiae Siren Ultimate Precision Glass File #10000-#12000

This file absolutely devours plastic bumps like gate marks, and does a very good job leaving a mirror shine that can be easily roughened with your choice of fine grit sandpaper. Works quite well on transparent plastics as a result. It does clog up with plastic in the ridges relatively quickly but even a swipe with a finger cleans it out much better than even scraping out an iron file with fingernails or most scraping implements does, with no risk of cutting the finger skin. It's a simple trick but it's shockingly effective.