The knife test is basically ASMR horror at this point, but was originally to identify plastic vs metal in frames and buttons, and also plastic vs glass on cam l

The knife test is basically ASMR horror at this point, but was originally to identify plastic vs metal in frames and buttons, and also plastic vs glass on cam lenses. The lighter test was originally to identify lcd vs led as they behave differently, but afaik nobody is even doing lcd anymore...