Adding Colour to Metal

Hello, Jewel Envy readers! Today I thought I would share with you a few of the ways we add colour to metal here at the studio. In the picture above, you can see three different pairs of earring each coloured with a different technique. The top pair uses a patina to achieve the black colour, the middle pair is anodized niobium and the bottom pair is coloured with enamel. In this post I’m going to give a brief description of each of these techniques so you can get an idea of how they work.

Patinas: Patinas cover a broad range of chemicals that can be applied to the surface of metals to alter the colour. There are two main types of patinas, hot and cold. Cold patinas, such as liver of sulfur and gun blue, can be used at room temperature and painted on or the piece can be dipped directly into the solution depending on the desired effect and the type of patina. Hot Patinas, like cupric nitrate need to be used with heat. In the case of cupric nitrate, the metal pieces are heated at an even temperature (this can be done on a hotplate) and the patina is painted on to the heated surface. Patinas create layers of oxidization to alter the colour of the metal. Basically they make the metal dirty in a controlled and even way. If your piece is fully patinated this means you never really need to clean it!

Anodizing: Anodizing is a process that only works with reactive metals, examples of these metals include niobium, titanium and aluminum. To achieve the vibrant colours that these metals are capable of, they need to be anodized. In order to anodize the metal, it must be hooked up to an electrical source as the anode (the positive side of the power source/battery) and dipped in an electrolytic solution (this sounds fancy but can be as simple as saturated salt water) with another piece of metal that is hooked up to act as the cathode (negative side of the battery). Once this is all set up the pieces are electrified at different voltages to achieve different colours, for example, 20 volts creates a vibrant blue while 70 volts gives you fuchsia. Anodizing essentially builds up layers of oxidization which is what creates the different colours. While anodizing can achieve some beautiful colours, one of the drawbacks of using reactive metals is that they cannot be soldered, so you need to get creative with how you attach niobium pieces together.

Enamel: Enameling is a process where glass is adhered to the surface of the metal to create different colours. Traditionally the glass comes in a fine powder (this can be turned into a paste) that is carefully applied to the surface of the metal either to create a solid colour, a pattern or even an image. Once the powder is placed the piece can be carefully placed inside a kiln and fired at high temperatures to melt the glass and make it adhere to the metal. Enameling can be done in layers to achieve more complex results. There are also different styles of enameling such as Cloisonne, where wires are used to create patterns and separate areas so that different colours can be applied to the piece without blending and Champleve, which uses cast or carved metal pieces with separate recessed areas to achieve a similar result.

These are just a few of the ways colour can be added to a metal surface. As you can see, each process gives you a completely different look. You can come check out some of the colourful pieces in this post at the studio!