Working in a well ventilated area is a definite must, outdoors is preferable. The odor of rotten eggs given off by liver of sulfur can be overwhelming if used in a closed area. It is easy to be put off by the smell but the results that can be achieved are simply amazing.
Liver of sulfur comes in two types. The liquid form can be used straight from the bottle, but the shelf life is unpredictable even when stored in a cool, dark place. Solid liver of sulfur is usually sold in small chunks, which are mixed as needed. For this reason, it is better to buy small amounts of the solid and make your solution mixing only what you need to create the most beautiful handcrafted jewelry.
For your solution, put a 1cm or 1/4 inch clump of solid liver of sulfur in a glass or plastic container with about 1 cup of water. The color of the solution should be a very pale yellow. A strong solution will develop the colors too quickly to stop the process at your desired color while too weak of a solution can take too long and build a thick flaky crust. Experiment to find the best concentration for the metal you are working with to get the results you want.
Set up your workstation so you can easily go from one step to the next. Have a heat source, the liver of sulfur solution, cold water bath and finally a soapy baking soda rinse. The secret is to control the process is the solution strength and the temperature. The hotter solution will react more quickly and the colors will move faster from one color to the next. They roughly go from gold, pink, blue, purple, gray and finally black.
Before you begin, your copper handcrafted jewelry in green patina should be clean and free from dirt or oils from your hands. Wearing gloves throughout the process is preferable. Liver of sulfur will begin to react the instant you put handmade bracelets or handmade earrings into it. Let the color develop for a couple of seconds on the handmade jewelry piece, then put in the cold water to stop the patina forming. Repeat these steps until you reach the desired color. Finally, rinse the piece in soapy baking soda solution to remove any liver of sulfur residue that could continue to change the color of the patina. Do not rub the handcrafted jewelry piece with the baking soda mixture as any abrasive will damage the patina finish you have worked hard to create.