Chemical imaging technique takes apart a painter’s process without injuring the canvas
When you’re in the art museum, seeing that a painting is made in “oil” or “mixed media” sometimes feels more like a formality rather than useful information. Fortunately, a new technique for paint analysis promises to add a lot more useful detail to those descriptions, revealing exactly which paints were used, and even what order they were applied to the canvas. Modern paintings produced with mass-produced commercial paints probably won’t yield many surprises, but by looking at the exact pigments and layering in older paintings, art historians will gain a much richer understanding how these paintings fit into the world that produced them.
The technique is called macroscale multimodal chemical imaging, and is actually a combination of earlier forms of chemical analysis. However, the combination of hyperspectral diffuse reflectance, luminescence and x-ray fluorescence can now produce data that offer more than the sum of their parts. Instead of simply giving researchers a graph of values, the technique uses each form of analysis to create images for each type of pigment used in a painting. The visual relationship of each layer of paint is then made much more obvious, as the strokes, revisions and essentially, choices of the artist are laid out for your eyes to see.
Making sense of materials
Additionally, this technique can identify the chemical composition of each layer of pigment. Knowing how each color was sourced can then provide insight into the difficultly, cost and importance of a painting at the time it was produced. For instance, a rare blue pigment used in a portrait indicates that the patron felt it was worth investing in those materials, helping historians better understand the story behind the painting.
Finally, none of these details need to harm the painting to be analysed. Many ancient objects are quite fragile, and so there’s an interest in avoiding destructive sampling, even if those samples are tiny. When working with ancient, one-of-a-kind artwork, deconstructing the artist’s process without taking apart the painting itself should prove to be a great new addition to historian’s tool kits.
Source: A New Scientific Technique Reveals How Ancient Humans Made Art by Taylor Dafoe, Artnet
