You may remember my short series on Bronzesmith, the foundry in Arizona that casts beautiful sculptures. One of the finishing steps I hadn't seen is adding the patina. While we were in Santa Fe, Bronzesmith employees were demonstrating this process at one of the many art galleries in town.
In his right hand is the brush for applying chemicals and in his left the torch for activating them. On a table were many small bottles of various chemicals for different colors. The process has been refined to the point that these patinas can simulate stone like turquoise.