This tian-tsui headdress dates from the 19th Century, and researchers are hoping to learn more about the feathers that provide its shining blue colour. Credit: Headdress (清朝 点翠头饰), Qing dynasty (1644 – 1912), 18th – 19th Century China. Promised gift of Barbara and David Kipper. The Art Institute of Chicago. CC0.

Analysis reveals just how much skill and precision went into Chinese tian-tsui featherwork art in the 18th and 19th centuries.

The kingfisher’s brilliant blue feathers were once used like paint to create works of art. The technique, known as tian-tsui, was popular during China’s Qing Dynasty. 

And because tian-tsui uses delicate feathers, previous scientists struggled to study them using traditional analytical techniques.

So, researchers developed new methods of investigating these featherworks without harming them. 

Working at the Center for Scientific Studies in the Arts, the team found that multiple bird species and layered pigments provided a one-of-a-kind palette. 

The shades of blue in kingfisher feathers are the result of a phenomenon called structural colour. 

Rather than being created by pigment molecules, structural colour is created by tiny, ordered structures in the feathers that interact with light to create the observed colouring — in this case, blue or purple. 

To gain insights into several featherwork pieces and the feathers that went into making them, Madeline Meier and colleagues combined different imaging and spectroscopy techniques that rely on the ways the feathers reflect and scatter light.  

The team analysed a decorative tian-tsui screen estimated to date from the late 18th to the early 19th Century that features intricate scenes in a variety of colours.

In one panel, analysis revealed that the blue feathers belonged to the common kingfisher, and the purple came from the black-capped kingfisher. 

The green feathers had different nanostructures than the blue feathers, leading the researchers to conclude that the green ones belonged to another bird entirely: the mallard duck.

Unexpectedly, they discovered that the magenta areas contained mercury(II) sulphide — likely from a red pigment called cinnabar that was used in Chinese artworks of this era — layered beneath purple feathers from the black-capped kingfisher. 

Meier said: “Colour in artworks and artifacts is a complex phenomenon occurring across material class and length scales from macro to nano.

“It really illustrates the skill and material knowledge that went into fabricating these beautiful works.”  

Next, the researchers will apply the techniques to other tian-tsui artworks, including a series of headdresses that date from the 18th and 19th centuries. 

They’ll also conduct further research, using synchrotron methods, to more deeply understand how nano-sized changes to feather structures lead to changes in perceived colour. The team hopes this work can inform future cultural heritage research into these understudied artworks.

The report is published in ACS Omega.