It’s Tuesday, July 25, 2017 and 79°F in Austin, Texas
Bob Atchison's Guide to Bronze Patinas
Make the right choice for your work of art
Most people do not realize that bronze statues have artificial patinas applied to their surfaces. Now we are not talking about ancient statues that have been dug up from the ground or raised from the seabed. Those bronzes have natural patinas that have taken hundreds of years to develop. Some ancient statues, like the bronzes from the Villa of the Papyri in Herculaneum have been restored and in the process have had new patinas applied. Only a few ancient statues — like the equestrian statue of Marcus Aulerlius from Rome have survived without being buried and possess their original surfaces.
I want to illustrate the various patinas and give you my recommendation on which finishes work best for your statue and its use. Here are some examples:
Here is the natural color of bronze when it comes out of the mold. It looks like brass or gold and the finish is very bright and shiny. The ancient Greeks and Romans actually preferred this which we find garish today. It is difficult to maintain — without waxing as a protective layer the surface of the bronze will inevitably oxidize and change. The process can be uneven, ugly and unattractive, with dark brown and green streaks developing. Over time the surface will even out, but this can take a very long time.
I remember many years ago the statue of Chief Seattle in Downtown Seattle was stripped of its green patina and it was decided to go 'natural' and let the real bronze color age. It was a horrible decision and the statue looked hideous in a year. So, the natural finish is never recommended. If you want this look it is better to go with gilding.
This is an applied brown patina. It is called Renaissance Brown because it was very popular in Italy in the 15th, 16th and 17th centuries.
During this period the art of large scale bronze casting was revived and craftsmen had to relearn all of the techniques that had been lost since Roman times.
The bronze finish works very well for small scale bronzes or statues that will be kept inside.
Some marvelous effects can be achieved with this patina when it is applied artistically and subtly. It can enhance fine casting and engraving of bronzes. You can't go wrong with this finish and it is a safe choice if you don't have experience with patinas.
Don't forget that you will need good lighting for any bronzes that are displayed indoors.
This patina is named for the surface color that has been used in the statues unearthed from the ancient town that was buried by Vesuvius in 79AD. In the 18th century the Bourbon rules of Naples unearthed a huge hoard of bronzes from the Villa of the Papyri (mentioned above). When these bronzes were brought to the surface almost all of them required extensive restoration. During the eruption most of the bronzes were thrown from their bases and crushed by flying stones, tiles and other things blown about by the powerful pyroclastic flow. After the statues were repaired the Bourbon restorers applied a green black patina to the bronze surface to level everything out and conceal any imperfections in the surface finish. At the time the discoveries at Herculaneum created a revolution in the decorative arts of the time. Every aristocratic home had to have a collection of bronzes from Pompeii and Herculaneum.
There were foundries in Italy that mass produced extremely high quality reproductions made from molds taken directly from the originals — all made with a Herculaneum Black patina. This popularized the color, which the romans probably never used. It works very well for outdoor sculptures, where it will age and develop beautiful natural green areas. It does not work well inside unless you have very bright natural or artificial light. The overall color is usually applied flat without any artistic modifications.
This is the color that is found on many ancient statues that have been buried in the earth or found on the sea bed. Many modern statues — especially outdoor ones — are given this patina to age them.
It shows up details very well and was popular in England and France in the 19th century.
It is very difficult to apply this patina well and it often creates irreversible damage to the surface of the statue it is applied to. It can be quite corrosive. One applied you are stuck with the results.
Unless it is applied like you see at left — in a flat overall fashion — only a great patina craftsman can apply it effectively.
If it is applied in streaks and blotches to resemble 'age' on a statue it can look fake and distract from the beauty of a casting. So, I recommend only using this patina a flat, overall manner.
Here you can see a very subtle combination of colors on a bronze bust that is intended for internal display. This work would never be placed outdoors.
If you can find a foundry that does artistic patinas you can create amazing beautiful surfaces like this. Most foundries only want to apply one patina and don't have craftspeople who have the talent to apply patinas like this.
It's virtually a lost art.
Combinations of colors require a delicate touch and an understanding of the natural aging of bronze and the subtle play of surface finishes like waxes.
There are many colors available for artistic patinas like blues and oranges, however unnatural colors are often garish and ugly.
In ancient Greek times statues were gilded by applying sheets of gold to a surface and locking them into channels engraved into the bronze surface. The Romans also work fine sheets of gold onto bronze statues using bone tools that burnished the gold onto the surface. Another technique involved the application of mercury and fired to forge the gold to bronze.
This technique of gilding is very dangerous and is outlawed in the European Union.
Today most gilding is electroplating and involves a electric current placing a very thin layer of color on the surface of the metal. There are many techniques to make the surface bright or matte. These are important to duplicate and essential for the recreation of decorative Empire period bronzes.
We have a foundry we use in Eastern Europe which does an excellent job making gilt-bronze pieces from original molds.
Pallasart offers reproductions of Empire and Neoclassical Bronzes. We also take special commissions. Please call us at 512 469-7454 to inquire.