Rokusho is the tradional patina used in Japan. The rich colors it creates on different non-ferrous alloys have never been duplicated with other processes.
 
The patination solution comprises roughly 4 grams each of Rokusho and copper sulphate CuSO4 (available at scientific supply stores) dissolved in 2 litres of water. A pinch of alum should be added. The solution is brought to a simmer in a pure copper vessel, and the piece immersed in the solution. Much care needs to be used in surface preperation and handling. Do not introduce ferris materials to the solution!
 
It will turn:
 
Copper: a rich orange to brown
Shibuichi: beautiful greys
Shakudo: deep blue to purple to black
 
Results depend highly on alloy composition, surface preperation, and soak time.
 
For mor info on the surface preperation and patination process visit:
https://www.jimkelso.com/japanpatina.html/tutorial.htm
 
Sold in 50g quantities (will make 12.5L of the solution)