Recently, I've come across a lot of posts, blogs and convos about coloring metals with patina. Everyone is searching for the perfect way to change shiny new copper, brass, and silver to appear like ancient relics, colored by time. Who new that there would be such a demand to look old? It is true, aged metals are gorgeous. Brass and copper turn shades of intense blue and green, silver can change to a virtual rainbow of colors, to deepest black. In this post, I will be sharing with you my experiences coloring copper, brass, and sterling silver. I also invite you to comment here, and share your tips and tricks. I'd also love to share photos of works in progress and finished designs using patina colored metals. Contact me with your photos and ideas!!
First, what is "patina"? According to Wikipedia, "Patina is a coating of various chemical compounds such as oxides or carbonates formed on the surface of metal during exposure to weathering. The green patina that forms naturally on copper and bronze is known as verdigris and consists of copper carbonate. Patina also refers to accumulated changes in surface texture and colour that result from normal use of an object such as a coin or a piece of furniture." Well, if you don't have the patience to wait months or years to let a piece of metal patina naturally, there are many chemical patinas commercially available that will do virtually the same thing in hours. My favorite sources for copper and brass patinas are Modern Masters and Michael's Crafts. Both offer a line of metal infused paints and chemical patinas that will change copper and brass to green, blue, brown and black. Simply spritz or brush on the patina of your choice and you can virtually watch the colors begin to change! The photo here is of a pendant I made using a solid copper bead I sprayed with green patina then sealed with automotive clear coat. I also always have brass ager on hand from Kennedy Hardware. This turns brass and copper deep brown to black depending on how long you leave it in the solution. All patinas must be sealed with a top coat or the colors may fade or flake off. Modern Masters sells a gloss and flat UV stable topcoat specifically designed for metals treated with patina. Otherwise you can try light coats of acrylic sprays. Use caution here, products not specifically designed for metals treated with patina can actually make your colors disappear (I speak from experience here...ugh!). A trick I use quite frequently for copper and brass is to spray on layers of automotive clear coat from my local Discount Auto Parts store. Acrylic spray for cars is specially formulated for metals and works quite well--giving a strong, durable finish without changing the color of the patina. 
There are also some great books out on coloring metal--I just got "The Jeweler's Directory of Decorative Finishes" by Jinks McGrath. A great source for patina ideas (and much more) with formulations you can make at home. Last night I tried the formula recommended for turning copper and brass indigo blue--something I have wanted to do forever. Simply take a medium sized plastic container with an air tight lid and place a smaller ( I used a baby food jar), open container of common household ammonia inside to one end ( I got the ammonia at my local grocery store in the cleaning products aisle). Prep your copper/brass by sanding, and wiping down with warm saltwater. Place the metal next to the open ammonia container. From here you can do a couple things to add texture to your patina. I sprinkled salt and vinegar on one piece of copper, left another bare, and left the brass bare. Cover the container with the airtight lid and leave for at least three hours up to overnight. You will be amazed at the color you get!!! The copper treated with salt and vinegar got a mottled, spotted coloration of deep blue and black. The untreated metals turned lovely indigo blue. When the colors reach your desired intensity, simply take the metals out, rinse thoroughly, pat dry and seal. Kind of magical actually....The book also describes a similar process to get that rich, blue color by burying the metal in an airtight container of sawdust, garden soil, and tobacco soaked with ammonia and vinegar! That appeals to my inner mad scientist/archaeologist. I like the idea of digging up the metal later, even if it is from a Tupperware container. I'm trying that one next... The photo below shows my ammonia experiment with (from left to right) a solid copper bead, a dome of brass, a fragment of copper sheet and a larger fragment of copper sheet. The large piece of copper had the salt/vinegar splashed on top. Don't you LOVE that blue? All were finished with Modern Masters UV flat topcoat.
Of course, you must be sure to do all of this in a well ventilated area--ammonia fumes are overwhelming if you are not careful. The commercially available patinas that I mentioned earlier are odorless and easier to use, but don't give the intensity of color that you get with the ammonia treatment.
AND, let's not forget the beauty of RUST. Rust is the poor step-child of patina. You don't often think of it as a desirable patina for jewelry, right? Well I disagree! Sophisticated Finishes (from Michael's) has a rust paint and patina set. The paint contains suspended iron particles that react with the chemical patina, turning the iron a lovely orange. I have used this with brass and copper, and love the result. I layer this with blue and green patinas, sand some off, add more--it's a process. To quote Forrest Gump, "You never know what you're going to get!"I haven't even touched on coloring sterling silver yet...I could go on forever! The most common chemical to color silver is liver of sulphur. Smells horrible, like rotten eggs, but is easy to use and you can get it at Cool Tools. It comes in chunk form--simply place a small chunk in a plastic or glass container of HOT water, and drop in your silver. Have another container of warm water mixed with baking soda on hand to immerse your silver in when you reach the desired color. The color change is immediate and will go from a lovely rainbow effect to deep, dark black in moments--so be ready to remove your silver right away. You can also brush on the liver of sulphur/water mix to better control your patina. Drop in the water/baking soda to stop the reaction and then rinse in cool water. Pat dry and seal.
Well, that's a start...I will be adding to this post as I get your responses--I hope you will join me in sharing your patina questions, secrets, ideas, and finished designs. Let's grow beautifully old together!!!
