In the video below I outline the method that David Marks teaches in his Chemical Patina classes. You can find a more detailed written article with a simple web search on Fine Woodworking Magazine’s website. David Marks published an article several years ago in an issue going into a great amount of detail not only on how to create these finishes but also which chemicals color which metals in a specific way.
The video here is a brief outline of that process. Also, below is a list of items I used to make these art pieces:

Enjoy the show!
Hello,
I watched the video and you did a good job explaining the process but you never said what kind of chemicals you applied to get the effect. Can you please explain more to me about the patina chemicals? Thank you
Yes, I wanted the viewer to search Fine Woodworking Magazine’s website for “Chemical Patina Finishes” to get further details. On silver leaf I like to use liver of sulfur. Barium sulfide on copper if you want to darken it up. Sodium sulfide on copper and dutch metal but it works fast. Cupric nitrate and ammonium chloride work on dutch metal.