Black Patina Mixture
You had mentioned mixing vinegar and salt to black patina; 1 TBSP white vinegar and 1 tsp salt....to how much patina?
AnswerUse only vinegar or salt, not both together.
None of this is an exact science, so it will take a bit of experimenting on your part. Start with 1/8 cup patina or however much you think you'll be using for the one project. You will dispose of the remainder of the batch. Also, use 1 tsp vinegar, not 1 TBSP, and see how that works. You can always add more if you need to. The same goes for the salt. Start with 1/2 tsp. If that isn't making the patina darker, add a bit more.
It's a good idea to keep records so that once you have it right you won't have to experiment each time.
I'm sorry that I can't be more specific. Perhaps someone reading this has a proven "recipe" that they use and would be willing to share with us.