I was surprised exactly how patination is both art and chemistry; regulated oxidation, acids

https://telegra.ph/Leader-Boxes-Developed-for-Generations-Hand-Fabricated-Copper-That-Does-Not-Compromise-07-04

I was surprised exactly how patination is both art and chemistry; managed oxidation, acids, and waxes produce living finishes that advance with weather yet continue to be protectively sealed.