History of Blue Paint from Medieval Times to Today
Paint in the Medieval Period
If you suddenly decided to paint a room in your house blue, you could go to a DIY store or shop online and find hundreds of different shades of this colour. But hundreds of years ago things were very different. Pigments were not always easy to make and some colours were more difficult than others. Although being one of the most sought after and popular colours, creating different shades of blue pigment or paint was a challenge in the early medieval period. In the middle ages, artwork was expensive to produce and so was generally only found in the hands of kings, nobles and the church. Monasteries produced exquisitely decorated illuminated manuscripts, wooden panels were painted for churches and frescoes were painted on the walls of religious buildings.
Making Medieval Paint
Paint is made up of a pigment combined with a binder and, unlike dyes, sits on the surface of whatever is to be painted, which needs to be an absorbent surface. In the middle ages a variety of binders were used such as oils like linseed and walnut oils, gum Arabic, or lime-wash. However, the most common binder was egg. Beaten egg white called glair was sometimes used, but most medieval artists used the yolk of the egg to make tempera paint. Using tempera was challenging because it could not be stored and used again, so the artist had to make the exact amount of paint that he needed to complete his work. If he did not make enough tempera he risked not being able to exactly match the colour when he made the next batch, or if he mixed too much he would be forced to throw away some very expensive ingredients. This was especially true if he was using blue pigment, because in medieval times artists generally used either azurite or ultramarine.
Azurite is a blue gemstone that contains copper and is found in many parts of Europe. To create the pigment, this very hard stone first had to be crushed and then moistened before being ground into a powder with a pestle and mortar. The final colour was determined by how much the gemstone was ground down; a darker hue was produced from the more coarsely ground azurite and a lighter azure shade from the finely ground gemstone. However, although it was expensive to purchase azurite and very time consuming to prepare the pigment, it was still not as costly or sought after as the deep, vivid blue ultramarine.
Ultramarine, like Egyptian blue, was made from crushing precious lapis lazuli that had been brought over land and then by sea from the distant Badakhshan mines in Afghanistan. The very name ultramarine means ‘over the sea’ and during the Renaissance this pigment was worth more than gold. So prized was it that two pots of this costly paint were recorded in the 1401-1403 inventory of the treasure of the Duke of Berry. It was valued so highly that it was even recycled and in the 12th century they carefully peeled it off the Winchester Psalter so they could use it again.
How to Make Ultramarine
In the early middle ages, artists and scribes usually made their own pigments so there were many different recipes for producing ultramarine. A fairly common method was to mix the crushed lapis lazuli with mastic, linseed oil or pine resin and then boil the ingredients together. The resulting mix was then soaked and kneaded with lye to extract the blue colour. The pigment was produced in batches, with the first batch creating the purest, deepest, brightest shade and this was sold for the very highest prices. The quality of the colour deteriorated as more batches were produced, dropping the value of the paint until finally the last batch, known as ultramarine ash, was made.
What They Painted Blue in Medieval Times
One of the reasons that blue was so prized in medieval Europe was that it was the traditional colour to use for painting the mantle of the Virgin Mary. The use of this hue was very symbolic, as it was thought to represent the heavens; symbolising the Virgin as a bridge between earth and heaven, a link from our mundane world to the numinous. Because of its expense, the use of ultramarine was confined to royalty, the upper ranks of the aristocracy and the more richly endowed monasteries and churches. There were some cheaper blue pigments available to medieval artists that were mainly derived from plant materials. They had use of a violet blue shade that was extracted from the seeds of a plant called tumsole, which today we know as Crozophora and lake pigments made from indigo or woad. There was also smalt, which was produced by grinding up blue potassium glass that contained high levels of cobalt. This became a hugely popular medium to paint with because it did not cost very much and the Flemish and Dutch specialised in its manufacture during the 17th century
Discovery of Prussian Blue
During the 17th and 18th centuries artists and scientists started to develop the first synthetic pigments and around 1706 Prussian blue was made for the first time. Its creation was actually an accident, as the man who first made it, a dyer called Diesbach, was experimenting in Berlin in the hope of producing a new shade of red. He planned to use potash and iron sulphate, but because he was trying to cut costs he bought a cheap batch of potash that had been contaminated with oil from cattle blood. He was looking to create a strong, bright red hue but instead ended up with a pale, wish-washy red. He added more ingredients hoping to strengthen the red, but instead got purple. He concentrated the solution even further and purely by chance produced Prussian blue, which is still used today.
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Invention of Synthetic Ultramarine
But the big prize was a synthetic version of ultramarine. The cost of this deep blue pigment had increased so much by the 18th century that only the very rich could afford make use of it. When he was in Italy in 1787, Goethe noticed that on the inside of lime kilns there was often a glassy, blue coloured deposit that he discovered was often used as imitation lapis lazuli. Similar deposits were found at the famous Saint Gobain glassworks in France, so a sample was sent to the Societe d’Encouragement pour L’Industrie Nationale for analysis. The results were so intriguing that they launched a competition that offered the huge sum of six thousand francs to any inventor or scientist who could put together a workable process for manufacturing synthetic ultramarine that cost less than three hundred francs per kilo.
Mass Production of Ultramarine
It would be four long years before someone stepped forward to claim the prize. In 1828 Jean Baptiste Guimet presented a manufacturing process that allowed him to create good quality synthetic ultramarine for four hundred francs a pound. As the genuine pigment made from lapis lazuli was at that time retailing for around five thousand francs a pound, this was a real godsend for the struggling artists who needed this deepest of blues to paint with. The synthetic version was darker than and not as intense as the natural pigment, but close enough that it could be used as an acceptable substitute. He did have a competitor for his process though, as at roughly the same time a professor called Gottlob Gmelin came up with an alternative, although similar way, to make a different synthetic version of ultramarine.
New Synthetic Colours
The Industrial Revolution saw many new colours being introduced, mainly to satisfy the rapidly expanding textiles industry. Natural dyes tended to be very expensive and they needed a much wider range of colours that could also be produced more cheaply. Scientists started to work with heavy metals in order to produce colour and Cobalt Blue first appeared in 1802 and was later followed by many other hues derived from cadmium and cobalt. Although these new colours were bright and relatively inexpensive to produce they had one big drawback; some of them were highly toxic.
Introduction of Aniline Dyes
But what would really destroy the natural dye industry was the invention of the first aniline dyes in the latter part of the 19th century. An English chemist by the name of William Henry Perkin was conducting experiments on synthesizing quinine, a drug used to fight malaria, when he noticed that one of his aniline mixtures had turned a brilliant colour of purple. This colour change fascinated him, so he tested it as a dye on cloth. He realised that this new aniline dye remained stable after the cloth was wash repeatedly and also that it did not fade when exposed to bright sunlight for a long time. Although he was only eighteen years old at the time, he took out a patent and called his new textiles dye mauveine. He then borrowed some capital from his father and started a factory that produced his new invention in large quantities. He was able to create lots of bright, new colours of aniline dye, including many shades of blue that considerably cut down the cost of mass-producing clothes.
So the production of blue paint has come a long way and now, instead of having only a few costly, natural pigments to choose from, we have a vast selection of different shades of paint and dye. So next time you pick up your paint brush give a little thought to the monks who worked for years on their illuminated manuscripts, eking out the precious azurite or ultramarine so they would not run out before they finished filling in the blue of Mary’s robe.
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