Asher gives us the lowdown on yellow metals. Part history lesson, part trend-alert, it's all-oy ever wanted to know about alloys. (Oy vey.) 

Here at DUNN's customer service desk, Jamie and I encourage clients to review our finish samples in person when making selections. Why? Well, simply put, one man's brass is another man's...trash. That is to say, just because it's called "brass" or "bronze" doesn't mean it's going to exactly match your other "brass" or "bronze" fittings. Yellow metals come in a wide range of hues and finishes, and we want our clients to know in advance exactly what to expect from our high-quality finishes.

So you say "patina", I say "patatta," let's call... Asher and get him to explain the whole thing! (Yeah, I went there. Dads all over the world are laughing.) Here's what he has to say on the matter...

Brass, bronze, and gold are the must have metals of the twenty-teens. Also known as the ‘yellow metals’ they were previously considered old fashioned but are, and have been for a number of years, trendy yet again with the influence of earthy and natural tones.

Above: Project by Matter of Architecture, formerly Leone Design Studio. Photo by Nick Glimenakis.

In the 20s and again in the 80s, the yellow metals were considered glamorous and ostentatious. They were often high polished and seen as gilding to make a space more fabulous and flashy. There is much speculation as to why these metals went out of fashion, and I lean towards believing it had to do with care and maintenance. Except for gold, which does not tarnish, brass and bronze require regular care to keep them bright and tarnish or patina free. With the advent of chromium plating, also known as chrome, that required little to no care to keep it bright, the yellow metals fell by the wayside to make room for chrome and stainless steel – low care and the wave of the future.

All good things come back around if you wait long enough. And sure enough, the yellow metals are hot again, though not in the flashy way they once were. It’s not so much the high polish and flash that make them attractive today but rather the various hues of yellows, greens, reds, and browns. These hues position the yellow metals squarely in the earthy and natural color palettes that are taking over today’s interiors.

You may be wondering what I’m talking about when I refer to hues of yellows, greens, reds, and browns. Except for pure 24 karat gold, yellow metals are a combination of metallic elements such as copper, zinc, tin, sliver, aluminum, lead, iron, and nickel, to name a few. The combination of metals creates what is known as a metal alloy. Altering the ratio of metal elements in an alloy changes its physical properties as well as color. Brass is an alloy of copper and zinc. Other metals may be added to achieve desired properties for strength, casting, or elasticity. Bronze is an alloy of copper and tin. Increase the quantity of copper in a gold alloy to make it redder, and increase the quantity of silver in a gold alloy to make it greener.

Brass and bronze are not only effected by the ratio of their alloys but also by oxidation, a slow chemical reaction that occurs between the alloys and oxygen. The chemical reaction causes a film to form on the surface of the alloys known as a patina, usually green, red, or brown, which may deepen the hue of the brass and bronze. Not all brass and bronze age equally, and patinas can occur unevenly and/or in a range of hues on a single part. I searched for as many brass parts as I could find and logged their hues on the below color map. As you can see, brass can take on many different hues.

In our studio we use all three yellow metals – brass, bronze, and gold. Many of our machined parts are made from solid brass because of its desirable machining qualities. We choose bronze for our cast parts because the bronze alloys make a smoother casting with less bubbling or surface pitting than brass. And although we call our surface finish ‘Brushed Brass’ in many cases it's actually a plating of green gold. This can be a little misleading, but gold plating ensures longevity of the finish you are purchasing because gold does not oxidize and will retain an even and consistent hue over time. We call it ‘Brushed Brass’ because the gold alloy we utilize is more relatable to the color of Yellow Brass (an alloy of 67 parts copper to 33 pats zinc) than gold. It’s a win-win: brass in color and gold in oxidation properties.

Patinas can also be manually applied to achieve the desired colors and textures. This usually requires a mineral or chemical applied to the surface of the alloy that sets a chemical reaction in motion. In some cases, a counter-agent is used to halt the reaction when the desired appearance is reached. Many aged or oil-rubbed finishes are achieved through hand applying an etching or darkening agent to brass or bronze. The hand application produces inconsistencies that speak to the hand-made quality. Patinas like this require a sealer to ensure the long-lasting integrity of the finish so it does not fall away or ware with use.

Because the yellow metals work with so many color and texture palettes, I don’t see them going away any time soon. Before you invest in yellow metals, I recommend requesting manufacturer samples to ensure the metals you’re purchasing work well with your palette, and consider unfinished versus finished (or sealed) brass when determining how the yellow metal will age in your space. Best of luck with your yellow metal endeavors!