Even thousands of years ago people wore clothing with colorful patterns made from plant- and animal-based dyes. Chemists from Martin Luther University Halle-Wittenberg (MLU) have created new analytical methods to examine textiles from China and Peru that are several thousand years old. In the scientific journal Scientific Reports
, they describe
their new method, which is able to reconstruct the spatial distribution of dyes, and hence the patterns, in textile samples.
Samples like these were examined by the chemists from MLU. (Image: Annemarie Kramell)
Chemists Dr. Annemarie Kramell and Professor René Csuk from MLU examined two ancient textile samples. One comes from the ancient Chinese city of Niya and was probably once part of a shirt. It is over 2,000 years old. The other sample comes from Peru and dates back to AD 1100 to AD 1400. It was produced by the Ichma people who lived in Peru at that time.
Today, there is often little evidence of the colorfulness of such ancient clothing. Over time, the natural dyes have decomposed as a result of the effects of light, air, and water explains the chemist. In the past, only natural dyes were used. René Csuk said:
Annemarie Kramell said: “Even back then, people mixed individual materials to create different shades,” adding:
The researchers have developed a new analytical method that allows them to detect which materials were used for which colors. With the aid of modern imaging mass spectrometry, they have succeeded in depicting the dye compositions of historical textile samples as isotopic distributions. Previously, the dyes had to be removed from the textiles.
With the help of their new method, the researchers were able to reconstruct the distribution of the dyes. (Image: Annemarie Kramell)
However, that previous method also destroyed the pattern. This new approach enables the chemists from MLU to analyze the dyes directly from the surface of the textile samples. To do this, the piece of material under investigation is first embedded in another material. Csuk explained:
Chemist René Csuk inspecting a textile sample. (Image: MLU / Michael Deutsch)
Similar methods are used, for example, in medical research to examine human tissue. The advantage is that this method can be used to study very complex samples on a micrometer scale. Csuk said:
As part of the new study, researchers were able to detect indigo dyes in the samples. However, the method can also be applied to many other dye classes and provides insights into the process of textile production in past cultures, the two scientists conclude.