The definition of a deep glass scratch can vary depending on the individual. A glazier who primarily replaces glass might consider any noticeable scratch too deep to repair. An inexperienced glass polisher might believe that any scratch catching the fingernail is too deep (a common perception found online). Generally, a scratch leaving a ragged edge, where tiny chips have broken out of the glass, is over 100 microns deep. Experienced glass polishers routinely remove such scratches unless they are too close to the edge. The most severe type of glass damage is known as “angle grinder splatter” or “spatter” in British terminology, typically exceeding 500 microns in depth. For information on whether this damage can be removed, please refer to our angle grinder splatter page.