Wednesday, February 27, 2008

Bronze Weathering

If you ever need to invent a bronze sculpture for a fantasy or science fiction painting, here are a couple of little tips to make the weathered surface more convincing.

I painted this oil study from observation to study how actual bronze surfaces weather. Note how the upfacing planes of the hat brim, the lapel, and the forehead are all oxidized to a light blue-green color.

The hollows and the downfacing planes weather in a different way as this photo shows. Instead of being entirely covered with a light blue-green oxidation, the downward planes tend to be darker and browner. This is because the downfacing planes are exposed to less rainwater. The top of the ball is also shielded from rain, and lacks oxidation. Wherever the planes face downward, the water is forced to flow in fixed rivulets. Each rivulet then becomes a line of oxidation.

You can play with this effect. This bronze head from the title page of Dinotopia: Journey to Chandara was entirely invented. Along the cheeks the rivulets almost look like the path of tears.

If the statue is in a public area, projecting forms are often buffed to a golden sheen from contact with the hands (or hides) of passersby.

As the rainwater drains off the statue, the dissolved oxides leave stains on the white marble below.

Tomorrow: Reply Card


Shane White said...

In another lifetime I created a weathering process for manufacturing of aluminum ornaments and resin sculptures that had to look like bronze, copper and even rust.

When you have to build it from the ground up, it certainly gives you a better understanding of how nature works.

I think I remember someone saying that Sargent would actually place the color of what he was mixing on the actual surface he was trying to replicated. Though it could have been Zorn...though he wasn't much of a colorist.


Victor said...

You never cease to amaze me with your observations of nature. You don't just paint what is there, but you understand it, as well.

Anonymous said...

This is very cool! Thanks for showing how bronze weathering looks. It'll help me a lot with my own illustrations, so cool that you're good enough to draw something that well just from imagination. I'm getting there.

Someday I'll be able to illustrate my own novels. And then decorate my blog, because a publisher would much rather buy from a well known illustrator than the author!