Patinating copper with all natural ingredients is such a satisfying experience. You don’t need chemicals, your general household ingredients will suffice. No need to wear gloves, respirators, dust masks, goggles, all that scary stuff! Take you vinegar and salt and make a happy stew, that’s all you need.
You do need clean copper, you can use dish soap, lemon juice, baking soda, etc. No happy patina will take on dirty copper. I use glass jars to hang my pieces to patinate. (Use wire or something like that.) I soak my pieces in the vinegar salt mixture and also sprinkle some salt directly on the piece. With experimenting you will find what will work best for you. You can also soak a paper towel in the mixture and put that on the bottom of the container. I cover mine with plastic wrap.
Then just watch and admire the wonderful color! Love the blue green when it starts developing. I’ve recently gotten such nice feedback on my copper patina pieces, there is something about the “all natural” funky patina that appeals to people. Yes, it does take time – after you get your patina you need to let it rest for a couple of days and dry out. Wash the pieces gently and let them dry well. Then you need to coat them with something that seals in the patina – wax, or some type of clear coat.
Not to forget that copper has health benefits, so go play!
A nice tutorial on all natural patina: