Specular reflection gloss meter.
https://www.youtube.com/watch?v=Sc5Re-XZQXY
Previously:
https://www.homemadetools.net/forum/...743#post159676
https://www.homemadetools.net/forum/...614#post159165
https://www.homemadetools.net/forum/...433#post158454
https://www.homemadetools.net/forum/...718#post143728
https://www.homemadetools.net/forum/...823#post137092
