Museums protect priceless artwork not just by using velvet ropes or security guards. They use science, too.
David McPhail is a chemistry professor with UT-Dallas. He’s been working with museums in North Texas on how to best preserve art. He talks about various techniques being used to help conserve art for future generations.
… on how new techniques can help conserve art: “In museums, generally speaking, things are changing very, very slowly. Let me give you a specific example: vessel glass. I did quite a bit of work on glass from Venice and other places which were hundreds of years old, and the rate at which that material interacts with the atmosphere and the moisture in the atmosphere is so slow that it’s imperceptible to the human eye. But over hundreds of years, we can build up millimeters of degradation on the surface. So, because things are so slow, we need techniques which have incredibly high precision. Ion beam spectrometry has the ability to look at the surfaces of materials with the precision of 1 nanometer or less.”
… on what to do after determining how a piece of artwork will degrade: “What we would normally do is look at what is the mechanism that is leading to the change of the surface. Oftentimes, it is the obvious things: So it’s moisture in the atmosphere, it’s oxidation, it’s dirt in the atmosphere depositing on the surface and blackening the object. One of the techniques I’m very interested in is laser-cleaning where we take a low power laser and we actually fire at the object and it couples with the dirt and the dirt is ablated but it leaves all the statuary material behind. But it turns out that actually sometimes dirt is quite good because it goes into the pores and the cracks on the surface of the sculpture and sort of blocks them up. If you clean it, you open up those pores and cracks again. And guess what? It gets dirty really quickly once again. Sometimes it is a good idea to actually think of putting some sort of lacquer or some sort of barrier film on top of the object to preserve from further attack.”
… on what museums are doing now to preserve their collections: “The environment itself is extremely carefully controlled in terms of temperature and humidity, and levels of illumination for objects that are light sensitive. If you’re going to the Dallas Museum [of Art], for example, you see that certain rooms have relatively low levels of illumination where that’s important to preserve the objects such as the textiles there. Most museums of any size will have a conservation laboratory where they have a team of people working on all sorts of different approaches for the vast range of materials that are in the museum.”
… on his work with the Andean textiles at the Dallas Museum of Art: “We’re fascinated by the fact that the colors in these textiles can persist with extreme brightness for hundreds and hundreds of years and the question behind that is how did they know what they were doing so well, how did they choose the dyes so well to maintain that level of quality and that’s one of the key research questions.”
David McPhail is a professor of chemistry with the University of Texas at Dallas.