The dye detective: unravelling Myanmar's history

From the dawn of civilisation until the mid-19th century, humans relied on the natural world to create colour. Ancient civilisations discovered the chromatic secrets of plants and animals, and that fibres retain colour when soaked in dye baths. This was the beginning of the art of dyeing that evolved over millennia – alongside the art of weaving – to create some of the most spectacular and culturally significant objects ever made… textiles. But, as the wheels of progress turned, a desire for autonomy from nature arose. In 1856 Sir William Henry Perkin obtained the first fully synthetic coloured molecule. Although the discovery was accidental, as Perkin was trying to synthesise quinine to be used in the treatment of malaria, it triggered a revolution in the world of dyes. Advancements in organic chemistry and the galloping industrial revolution created the perfect environment for the synthetic colourant industry to thrive. In a few decades hundreds of new chemical formulations were patented and put on the market.

As a scientist in the Department of Scientific Research at the British Museum, my primary role revolves around understanding what objects are made of and how materials evolve over time. My focus is the fascinating realm of organic materials, from ancient natural resources of plant and animal origin to modern synthetic polymers such as plastics. At the heart of my research lies a captivating journey into the history and composition of textiles and their dyes, from the ancient hues of the natural world to the vibrant palette born of synthetic chemistry.

When I try to identify dyes in textiles, the analytical technique that I use looks at the molecules that compose each dye. With just 2–3mm of a single thread, I extract the dye using a solvent mix. I then analyse this solution using high-pressure liquid chromatography (HPLC) and mass spectrometry (MS) to separate and detect molecules based on their masses. Most dyes have a unique combination of molecules, which is specific to the plant, animal, or synthetic formulation it originates from. But to determine these unique combinations, my most important task is to create a comprehensive molecular database of colour by analysing numerous reference materials representing historical sources of dyes. The colour database is like a reference library, from which I can confidently identify dye sources in samples from historic textiles.

However, navigating the fascinating world of dye analysis at the British Museum brings its own set of challenges. Picture this: one day, I am scrutinising textiles from South America, and the next, I am dealing with the intricacies of East Asian fabrics. The vast collection at the Museum spans the entire globe and stretches across millennia, from ancient archaeological textiles to contemporary fabrics. Another of my key tasks is therefore to forge collaborations and find ways to access relevant reference materials, crucial for constructing the database. Imagine trying to collect diverse reference materials when the natural resources vary so drastically across different regions! But the real challenge comes with modern textiles. Many 19th-century synthetic dyes are no longer in commercial circulation today. To track them down as reference materials, I had to embark on a quest for historical sources like old dye pattern books or collections of old chemical dyes. Collaborations are, again, crucial and the one I developed with the Society of Dyers and Colourists has been fundamental to create the molecular database of synthetic colours that I am currently using in the Museum's laboratory. 

The Burma to Myanmar exhibition displays a wide range of textiles, including those made by the Karen peoples; a diverse group who live in lower Myanmar and other areas, as well as in Thailand. Karen textiles stand out with their vibrant, complex and colourful patterns, meticulous embroidery featuring Job's tears seeds (Coix lacryma-jobi) and the use of ikat-dyed fabrics (an ancient kind of tie-dyeing that uses resist dyeing techniques) with distinctive motifs. One area that the exhibition explores is the introduction of new imported materials into local manufacturing practices, with particular attention to the role played by Britain and Europe in the colonial period (1826–1948). The timing of British colonisation of Myanmar aligned with the invention and global export of synthetic dyes from Europe. This period of transformation raises intriguing questions: How did local communities, particularly the Karen peoples, receive these novel materials? What forces guided their integration into local practices? To answer these questions, the lead curator of the exhibition, Alexandra Green, and I selected six textiles from the collection, dating back from the 1830s to the early 1900s. These carefully selected pieces serve as windows into the past, offering glimpses into the types of natural dyes embraced by the Karen peoples and the introduction of synthetic dyes into their textile-making practices.

My reference library of Southeast Asian natural dyes includes most of the plants and insects historically used in this area. I found that the natural dyes used in the Karen textiles were mostly local. Indigo emerged as the key dye in all shades of blue and green when mixed with yellow dyes. The root bark of the Morinda citrifolia plant was the source of the distinctive brick-red hue in these fabrics. For deeper and pinkish shades of red, the lac insect (Kerria lacca) was used, a practice rooted in centuries of tradition across India, Southeast Asia and other parts of Asia. Yellow threads drew their colour mostly from turmeric (Curcuma longa), a familiar spice also used in cooking. However, a delightful revelation awaited in the analysis of the oldest textile in the selection – an early tunic from the late 1830s to early 1840s. The yellow threads, in this case, owed their hue to gamboge, a gum resin obtained from various Southeast Asian trees of the genus Garcinia. Known for its bright yellow pigment, gamboge has a history of use in painting, but my analyses marked the first scientifically verified instance of its use as a dye in Southeast Asian textile production.  

Another standout revelation unfolded from a beautiful skirt included in the exhibition. Crafted with meticulous care, this skirt emerged as a testament to the artistry of dyers and weavers, predominantly using cotton threads but adding a few silk highlights woven into the decorative pattern. Among these silk threads are two narrow yellow vertical strips that were dyed with the colourant extracted from the inner bark of the Chinese cork tree (Phellodendron chinense). This dye, definitively of Chinese origin, raised a curtain on the textile's journey, showing that these silk threads were not dyed locally, but were imported from China already dyed. Why these silk threads make a cameo appearance only in select areas of this textile remains a mystery, making the skirt particularly special. 

There is another remarkable Karen textile in the exhibition – a woman's shirt made before 1863 and showing exceptionally rich embroidery of Job's tears seeds and red felted wool stripes. Wool is not a typical material in Myanmar and its presence already hints at a tale of imported materials. The dye analysis adds an extra layer to the narrative, unveiling a palette that resonates with European influences, such as red from cochineal (Dactylopius coccus) and yellow from the young fustic tree (Cotinus coggygria). The cochineal, sourced from Latin America, was a sought-after dye in Europe during that era, reinforcing the notion of materials making cross-continental journeys to craft this exquisite shirt, which actually had another secret to reveal...

Some of the embroidery threads in this textile are bright orange and lime green. The intensity of these hues sparked curiosity and led me to ponder the possibility of synthetic dyes, as achieving such brilliance with natural dyes seemed improbable. However, the analysis yielded surprising results: I only detected a small amount of lac dye in the orange sample and indigo in the green sample. Lac dye is red and indigo is blue, so these dyes did not justify the colours of these threads. Something was missing from the picture. It was only when I observed the samples using the scanning electron microscope (SEM) that I had a clue about what might be going on. A fine distribution of particles on the surface of the cotton fibres hinted at the presence of some inorganic material. I was eventually able to identify this material as 'chrome yellow' (lead chromate) or 'chrome orange' (lead bichromate), a non-plant-derived colourant. The process of colouring fibres with chrome yellow was developed in Europe in the 1820s and involved immersing the fibres in a lead salt solution followed by a potassium chromate solution. The result? Yellow particles made of lead chromate formed directly on the fibres through a chemical reaction. 

What makes this discovery so interesting is its rarity. The use of chrome yellow in historical textiles had been scarcely reported, and the process was deemed damaging to fibres, fading into obscurity with the advent of yellow synthetic dyes. However, our findings shattered these assumptions. Chrome yellow was not only more prevalent than thought but endured for much longer, as we identified it in yellow, orange and green threads from two more Karen textiles. 

The intrigue deepened when we considered the coexistence of natural dyes with chrome yellow. In these green and orange threads, chrome yellow played host to an over-dyeing of blue (indigo) and red (Morinda citrifolia or lac dye), respectively. What makes this truly captivating is that these natural dyes are indigenous to Myanmar. It became clear that Karen dyers were receiving cotton threads from Europe pre-dyed with chrome yellow, then ingeniously over-dyeing them with local dyes to transform the imported threads into a spectrum of vibrant colours. 

These results have revealed a vibrant tale of creativity and adaptability. Far from merely incorporating new imported materials, dyers and textile-makers in Myanmar actively experimented, transformed and moulded these novel elements to suit their preferences. This was further confirmed by the analyses of three additional Karen textiles, uncovering a fascinating fusion of natural and synthetic dyes. 

In the broader context, the Karen textiles and their colours paint a picture of Myanmar as a land deeply interconnected, with numerous networks built before, during and after British colonisation. During the colonial period, new materials spread fast and reached not only the main cities and ports but also relatively remote regions. The invention and spread of synthetic dyes represent a chapter in European history often told from a Eurocentric perspective, adopting a simplistic narrative that describes how synthetic dyes wiped out natural dyes all over the world within a few years of their invention, partially reinforcing views of European supremacy in colonial times. This research shows that the narrative is much more nuanced. Synthetic dyes did not obliterate centuries of traditions overnight. This research reinstates agency to non-European dyers and textile-makers who actively shaped and evolved their practices amidst the changing tides of history and material culture. 

The findings of this research resonate with the themes of the Burma to Myanmar exhibition, which underscores the diversity and interconnectedness of the country, and the resourcefulness and skill of its people. These insights into Myanmar's material cultures open a window not just to the objects on display but also to the people who, through their craft, have woven their story across time and artificial borders.