Dye another way: the secret agents of colour
Research is being done to preserve ancient icons and textiles around the Mediterranean. The plant and insect pigments of the past are being rediscovered by means of modern technology. After years of poorly completed restorations the historical treasures are finally being given back their true colours.
The 200-year-old church of a small village in north-eastern Greece is the proud host of about 50 precious post-Byzantine icons. Most of them are works of the distinguished Galatista School of Icon Painting. These icons are seen as historical works of art and tools of Faith. In Greek Orthodoxy the icons are a source of faith for believers and play an active role in worship.
The invaluable items undergo preservation work at a nearby laboratory. To be able to preserve the icons without repainting, the artist, school, painting techniques and time of previous restorations is first established. Before cleaning the layers of colour and varnish are carefully analysed.
It is important to protect the varnishing layers, which are cleaned or removed using solvents. Unfortunately these solvents can damage the colour layers. It is at this point necessary to identify the pigments that were used and their concentrations. With this knowledge the correct solvents could be used to protect the icon without damaging its colours.
Identifying pigments used in the Mediterranean for icons, murals and textiles is the aim of the European research project Med-Colour-Tech. The results of the project should improve the preservation techniques for historical artwork.
Pigments used for colouring can be either organic (e.g. plant or animal) or inorganic (e.g. minerals). At the Research Centre in Ormylia, in North-east Greece, spectrographs are completed for microscopic samples of the icons in order to find out what substances were used in making the pigments. For pigments of organic origin chromatography is used to find the species of plant or insect that were originally used in the production of the dye.
Just as important as the ingredients is the method for making the dye. The Med-Colour-Tech project is reproducing the traditional colouring techniques from the Mediterranean and renewing them with a modern physicochemical approach. After establishing the production methods in the laboratory they will be prepared for industrial scale production.
Scientists are also renewing ancient colour recipes at the Faculty of Fine Arts of the University of Marmara in Istanbul. The old methods are used and then experimented with until the exact same pigment is created as the historical one. To perfect the colour variables like the amount of organic compounds, temperature or dissolving time are altered. Around 200 different types of plant and 5 insect species are being used to create the various colours and tones.
One application of the successfully restored dyes will be the reparation of ancient Anatolian carpets. Ali Osman Aykul is a carpet restorer from Istanbul. His workshop is a great source for scientists wishing to study timeworn historical carpets, some of which are 200 years old. He explains that for many years synthetic products were used for dyeing, which faded away very quickly. Now textiles dyed with organic pigments that result from technical research are being used. “The result is far better,” says the 20 years experienced carpet restorer. “Colours don't fade away any longer.”
After having standardised the dyeing processes with organic materials, historical artefacts will be able to be restored to their truly original appearance.