Titanium is one of several metals that can form colorful oxide coatings, with the thickness of the coating determining the color. (The color comes from the fact that the thickness of the coating matches the wavelength of one or another color of light.) Niobium earrings are a good example, as are bismuth crystals. But this is the first time I've seen an actual painting made out of different thicknesses of oxide. My guess is that they used a brush connected to a battery, with the other end clipped to the titanium plate. By varying the voltage and/or time they could vary the thickness of the oxide coating and thereby form different colors.
It's quite remarkable that this was made in the 1970's when titanium was even more exotic and expensive than it is now. It must have been quite expensive to produce, and it's an interesting and quite beautiful piece of art, but I'm going to hazard a guess that it was not successful as art. This guess is based largely on the fact that people in the art world are incredibly bad at recognizing really interesting ideas until someone else tells them it's OK. Titanium doesn't have a lobby in the art world. (The snobbery of the contemporary art world is based on the deep insecurity that comes from having no real basis for preferring one piece over another, or one artist over another: You have to rely on fashion, which is another word for what everyone else thinks. It hasn't always been this way: Back when you had to be able to paint to be a painter it was much easier to tell what was good painting and what wasn't, and people were more relaxed.)
Source: eBay seller hoosier981
Contributor: Theodore Gray
Acquired: 10 August, 2004