If you’ve left plates coated with egg for a while, you’ll know how difficult its residue can be to remove. No one knows when people first took advantage of this in paints, but earliest surviving examples date from late classical times. By the Renaissance, egg yolk was popular as a binder in artists’ paints, and the technique of egg tempera was used to create many of the masterpieces of the day.

Pure egg tempera technique uses the proteins, fats and other constituents of the yolk of fresh hens’ eggs as its binder; being water-based, water is its diluent. Applied thinly to an absorbent ground such as powdered chalk in a gesso, this quickly sets to form a hard if not brittle paint layer which, unlike glue tempera, can’t readily be removed by water.

Because egg tempera forms such a hard paint layer but is applied thinly, it’s prone to cracking unless the support is rigid and doesn’t change dimensions over time. Early egg tempera paintings were almost exclusively made on wood, but more recently stretched canvas has been used instead. That can lead to cracks and eventual mechanical failure of the paint layer. Egg tempera on wood panel was the favoured combination for easel paintings during the early Renaissance, particularly in Italy.

The finest paintings in egg tempera use only fresh eggs; as eggs age, particularly when they’re not refrigerated, separating the yolk becomes more difficult, and the resulting paint layer doesn’t appear as strong.

Since the nineteenth century, some paint manufacturers such as Sennelier have offered tubed paints with egg as their main binder, but with the addition of some drying oil to form an egg-oil emulsion. These have some of the properties of pure egg tempera, but are more versatile in their handling, and can be used like gouache and even, to a degree, like oil paints. These appear to have been derived from recipes recorded during the Renaissance.

Earliest European examples of egg tempera, such as Margarito d’Arezzo’s The Virgin and Child Enthroned, with Scenes of the Nativity and the Lives of the Saints from the middle of the thirteenth century, often incorporate extensive gilding and today might appear ‘primitive’.

Even the earliest paintings in egg tempera can be remarkably well preserved, such as Duccio’s Healing of the Man born Blind from the early fourteenth century. Although it only forms a thin paint layer, egg yolk is sufficient to preserve high levels of chroma in the pigments.

As the modelling of flesh and clothing became more realistic, egg tempera proved more than sufficient for the task.

One of the finest early works painted entirely in egg tempera is the anonymous Wilton Diptych in London’s National Gallery. Thought to have been made in France at the end of the fourteenth century, its exquisite detail would have been painted in multiple thin layers using fine brushes, much like miniatures painted on vellum.

But it was in Italy that painting in egg tempera reached its apogee, with masters like Masaccio, in his Santa Maria Maggiore Altarpiece from about 1428-29 (above) and Piero della Francesca’s Baptism of Christ (below) of a decade later.

During the fifteenth century, egg tempera was progressively replaced by oils in Italy, as it had been earlier in the Northern Renaissance.

Uccello’s large panel of the Battle of San Romano incorporated some drying oils, including walnut and linseed, although it was still fundamentally painted in egg tempera.

By the end of the fifteenth century, many studios had changed to oils. Among the last large egg tempera paintings are Botticelli’s Primavera (above) and The Birth of Venus (below), from the 1480s. The craft labour involved in producing these large works must have been enormous. Although Primavera was painted on a panel, Venus is on canvas, making it more manageable given its size of nearly 2 x 3 metres (79 x 118 inches).

In the closing years of the fifteenth century, Michelangelo kept to the hallowed tradition of egg tempera on wood in this unfinished painting of the Virgin and Child known now as The Manchester Madonna. This shows how he painstakingly completed each of the figures before moving onto the next, and the characteristic green earth ground.

By this time, the only common use for egg tempera was in the underpainting before applying oils on top. This remains a controversial practice: performed on top of gesso ground it can be successful, but increasingly studios transferred to oils. Egg tempera didn’t completely disappear, though. With so many fine examples of how good its paintings both look and age, there were always some artists who have chosen it over oils.

Some nineteenth century movements that aimed to return to the more wonderful art of the past experimented again with egg tempera. In the late 1870s, John Roddam Spencer Stanhope started to use the medium, and made one of his finest works, Love and the Maiden (1877), using it.

A later exponent who was rigorous in his technique was Adrian Stokes, who used it to great effect in this landscape of Autumn in the Mountains in 1903.

But for my taste, the greatest painter in egg tempera since the Renaissance has to be one of the major artists of the twentieth century: Andrew Wyeth (1917–2009). As his works remain in copyright, I recommend that you browse his official site, where you can see just how effective egg tempera can be in the hands of a great master. It may not be as popular as in the past, but egg tempera still has a great deal to offer.

Blue pigments used in painting include some of the oldest used by man, and others that led the change to modern synthetic pigments driven by the arrival of chemistry in the eighteenth century. This weekend I look at two examples, today the queen of pigments, ultramarine, and tomorrow the first synthetic chemical, Prussian blue.

Originally made by crushing and grinding the semi-precious stone lapis lazuli, the cost of ultramarine has exceeded that of gold. Seen in paintings, it produces a rich slightly reddish blue which stands the test of time, as distinctive and effective today as when it was first used. And its use has a history of unmasking fakes and forgeries.

The sole source of lapis lazuli in Europe and the West were quarries in Badakshan, described by Marco Polo and now in Afghanistan. It appears that wall paintings made around 507-554 CE adjacent to the great Buddahs of Bamiyan were the first to have used the mineral as a pigment. It was then used in early Persian miniatures, and in early Chinese and Indian paintings too. Tragically, these wall paintings in Bamiyan, Afghanistan, were damaged by the Taliban in 2001 when the two statues were destroyed, and their restoration has made little progress since.

The powdered pigment had made its way, first along the Silk Road, then by sea, to traders in Venice by about 1300. By the Renaissance, it was established as one of the most important and precious of all the pigments used in European art.

Because of its beauty and high cost, ultramarine blue was used for the robes of Jesus Christ and the Virgin Mary. Duccio’s panels from the Maestà Predella, including this of The Healing of the Man born Blind, show this tradition in its earliest years, around 1307-11. As a pigment, it proved practical in egg tempera as here, and in oils, watercolour, and fresco.

Ultramarine blue has been found in the van Eyck brothers’ Ghent Altarpiece from about 1432 (above), and particularly in its most famous panel, The Mystic Lamb, below.

Sandro Botticelli’s early tempera on panel painting Adoration of the Kings from about 1470, apparently made with Filippino Lippi, shows two different blue colours and purple. He painted the purple with an opaque underpainting of lead white tinted with a red lake derived from madder, to create pink. That was then glazed with quite coarse particles of ultramarine blue, so the pigment was thinly dispersed.

Peter Paul Rubens used ultramarine blue widely in his magnificent triptych now in Antwerp Cathedral. In its centre panel, Descent from the Cross (1612-14), it has been found combined with indigo and other pigments.

In van Dyck’s Charity from 1627-8, its most obvious use is in the blue cape, where ultramarine blue was painted over indigo, applied as both a tint and as a glaze over the top.

Visit any of the larger galleries with substantial collections of paintings made before 1700, and you will see works with drapery that I can only describe as arresting in the brilliance of their ultramarine blue. One stunning example in the National Gallery in London is Sassoferrato’s The Virgin in Prayer from 1640-50. The Virgin’s cloak looks as if it was painted only yesterday, and that colour makes you stop in your tracks and draws you into the painting, like no other pigment can.

Given its importance, and limited supply, considerable effort was devoted to ensuring that natural ultramarine blue was of the highest quality, and alternative sources were sought. Deposits in the Chilean Andes, and near Lake Baikal in Siberia, weren’t developed until the nineteenth century, and attempts to make synthetic ultramarine proved unsuccessful until 1828, when Jean Baptiste Guimet was awarded a prize of six thousand francs for his discovery. Almost simultaneously, C G Gmelin of Tübingen discovered a slightly different method.

Commercial production had started by 1830, and it became known as French ultramarine, to distinguish it from the natural pigment. Although almost identical in colour and performance, there are significant differences between natural and synthetic ultramarine when tested in the laboratory. This has enabled the examination of paintings to determine the source of their pigment, and has brought some surprises. These most often relate to later overpainting during restoration. For example, two areas of much later painting have been discovered in the van Eycks’ Ghent Altarpiece.

Examination of Édouard Manet’s Corner of a Café-Concert, from 1878-80, has shown that he used synthetic ultramarine in its blue passages, for example.

Pierre-Auguste Renoir’s The Umbrellas, from about 1881-86, uses synthetic ultramarine in a methodical fashion. The first stage in its painting used only cobalt blue, but in its second stage synthetic ultramarine was applied extensively.

Vincent van Gogh’s A Wheatfield, with Cypresses (1889) contains synthetic ultramarine in its deepest blues, and in some areas of green, although it’s unusual to find ultramarine mixed to form green. Before synthetic pigment became available, this would have been far too expensive a way of making any significant amount of green, but once much cheaper pigment came onto the market, that became more feasible, if still unusual.

The ability to distinguish synthetic ultramarine, which didn’t exist before about 1828, and the natural pigment has proved important in detecting some forgeries. Only the most ignorant would attempt to pass off a painting made with synthetic ultramarine as being very old, but a few fakes fell at that hurdle.

Han van Meegeren was far too knowledgeable and cunning to be caught so easily. He used natural ultramarine, for example when he sold The Men at Emmaus (1937) to the Museum Boijmans Van Beuningen as a Vermeer. What no one knew at the time was that his ultramarine looked genuine, but had been contaminated with a small amount of cobalt blue, which wasn’t discovered until 1803-04, and was first used as a pigment in 1806.

In 1960, the modern artist Yves Klein worked with the paint supplier Edouard Adam to ‘invent’ a paint he termed International Klein Blue (IKB). Although its formulation is a secret, it’s almost entirely synthetic ultramarine blue pigment in a polyvinyl acetate binder.

Like all the best queens, ultramarine blue has an unnerving habit of revealing the truth.

Reference

Joyce Plesters (1993) Artists’ Pigments, vol 2, ed Ashok Roy, Archetype. ISBN 978 1 904982 75 3.