This final article in the series draws together the details from the previous articles to produce a chronological summary of the major milestones in the materials and techniques of painting in oils.
Before 1150 – drying oils
The ancient Mediterranean civilisations knew that some vegetable oils ‘dried’, and some did not. They used pigments which could readily have been ground with drying oils, and had surfaces which could have taken oil paint. But they lacked organic solvents in sufficient quantities, so were unable to dilute oil paints or to clean painting tools properly.
c 1180 – 1400 – first oil paintings
The earliest known and dated painting which uses drying oils is that of the altar frontal at Tingelstad in Norway. By this time, small amounts of solvents including alcohol (earliest) and turpentine (from pine resin) were becoming available. Over this period, the primary drying oil used was that extracted from the common flax plant, widely distributed particularly in northern Europe – linseed oil.
1400 – sophisticated painting in layers, glazes
Control over paint viscosity was accomplished using pre-polymerisation of drying oil (with heat), adding resin thickeners such as pine resin, and solvents such as turpentine, which was now widely available. Drying time could be controlled by the addition of siccatives, such as lead and copper salts. These enabled greater sophistication in the use of layers, the application of transparent glazes, and finely detailed realism – characteristics of the Northern Renaissance.
c 1445 – oil painting introduced to Italy
It is unclear who first brought oil painting to the Southern Renaissance, but one of its first exponents was Niccolò Colantonio (c 1420-1460) in Naples.
One of the first Southern Renaissance painters to match the achievements of the north was Antonello da Messina (c 1430–1479), who was an early user of walnut oil (which was more readily available around the Mediterranean) as his primary drying oil.
By about 1490, the Southern Renaissance painters, including the Bellinis, were advancing techniques independently of the north.
c 1470 – painting on canvas
Mantegna (1431-1506) popularised stretched linen as the support for his distemper (glue tempera) paintings during the latter half of the 1400s. These became particularly popular in Venice, whose maritime climate made fresco unsatisfactory, and where demand from churches led to early production of very large oil paintings on stretched canvas.
1500 – wet-into-wet, simpler layer structures, broken marks, visible brushwork, sfumato, impasto
In the north, Lucas Cranach the Elder in particular developed a rich repertoire of techniques supported by fine control of paint viscosity and drying time. These were mainly used for depicting fabrics and flesh.
In Italy, Leonardo da Vinci used soft blending, sfumato, painting wet-on-dry; Giorgione and others developed wet-into-wet techniques.
As early as 1501, Giovanni Bellini and Giorgione started to use impasto, initially in fine details of fabrics, metalwork, and jewellery, where those details were applied in the upper layer of paint. Impasto passages were soon used by many Italian artists, and found their way to northern Europe by way of Martin van Heemskerck, who visited Rome between 1532-36.
c 1625 – complete versatility in paint
Although earlier oil painters had managed very good control of paint viscosity and handling, it was probably Rubens who achieved the most remarkable levels. Upper layers of his paint were applied using a wide variety of techniques, using paint which ranged from thin (diluted using turpentine) to the buttery and even stiff. His paint was stiffened by boiling the oil down or possibly by adding small amounts of egg white (there is doubt over that, as it may result from misinterpretation of paint analyses), seldom by using resins, and was applied most commonly in highlights, where his brushmarks remain apparent.
c 1650 – manipulation of surface texture
Over the period 1650-60, Rembrandt became the first major oil painter to exploit the visual effects achieved by manipulating the surface texture of the paint layer, which significantly alters its optical properties.
c 1750 – colourmen, bladders, and plein air
Artists’ colourman appeared during the 1700s, supplying stretched and primed canvases, prepared oil paints, and other materials. Oil paints were supplied in small airtight bags, often made from a pig’s bladder. These enabled painters to work without the support of a large and expensive workshop, and made oil paints much more portable. No longer was the painter constrained to using oil paints in the studio, but they could take a lightweight easel, small panels or canvases, and some bladders of paint outdoors, and paint en plein air, with the landscape in front of them.
c 1780 – the perils of rapid surface drying
Some painters, including Sir Joshua Reynolds (1723–1792), endeavoured to recreate the effects achieved by Rubens and Rembrandt. A popular basis for this was Megilp, a medium modifier consisting of drying oil heat-treated with drying agent (usually litharge) and resins. This has resulted in many problems in their paint layers, including extensive surface cracking and the rise of still-liquid paint from lower layers. Despite these obvious problems, several painters continued to use Megilp and other dangerous methods through the twentieth century.
c 1850 – tubes
John Goffe Rand patented what he termed “metal rolls for paint” in 1841. Although initially expensive and only used for new paints using the latest pigments, they were adopted almost universally by the late 1800s. Coupled with a lightweight easel and pochade box, they made plein air painting even more feasible.
c 1870 – alla prima and the deliberate impression
Direct painting, alla prima, in which there are only one or two layers, including any underdrawing, had been used intermittently since about 1500, often unsuccessfully. It was standard when painting en plein air, and became increasingly popular in studio painting too during the 1800s, particularly after about 1870. Although often associated with the Impressionists, many of their paintings consisted of complex layers (without glazes) applied wet-in-wet and wet-on-dry, sometimes over periods of several months.
By about 1900, even more traditional painters in oils such as John Singer Sargent, Joaquín Sorolla, and Anders Zorn were using virtuoso combinations of techniques, often well away from their studios.
c 1900 – industrial manufacture of paint
Oil paint manufacture was transformed from a small-scale craft to an industrial process, supported by technical developments of industrial chemists. Tubed paints contained elaborate systems of additives, to promote flow and handling, and achieve a consistent buttery feel irrespective of pigment. Pigments were ground more evenly, using machines, leading to more controlled and even quality. Research, led by conservators, brought much better understanding of the process of drying, and how paint layers can fail.
1976 – alkyds
Industrial chemical research brought a new type of resin for paints in the 1930s: alkyds. Much faster-drying than paints using traditional drying oils, they were first offered in artists’ paints in 1976. Although alkyd paints have not become popular, the use of alkyd resins as a medium modifier, to accelerate drying, has become far more popular. Since 2000 many painters have used them for alla prima work and in intermediate layers. However, when used over slower-drying layers they can cause problems.
c 2000 – just add water
With rising concerns over the toxicity of organic solvents (turpentine is particularly irritant and potentially toxic), and their environmental problems, many oil painters have now switched to using what have quite incorrectly been described as water-soluble oil paints. These consist of a supension of fine particles of oil paint, still with their drying oil included. Carefully packaged with a series of additives such as surfactants – detergents, as they are more commonly known – these are extremely convenient in use. They are also as yet unproven over the timescales that we currently expect of fine art paintings.
Deepening understanding of oil paints among conservation experts and the array of scientists who now support them has raised a new issue in oil painting technique: the threat of soap formation in the paint layer. Given the presence of water, additives such as surfactants, and certain metal salts, oil paint can slowly transform into mechanically weak soap, rather than polymerising into a robust paint layer. This can also occur when oil paint is applied to acrylic grounds, which have become popular.
We still have much to learn about oil paint, painting with oils, and how to make paintings which will last as long as those of Rembrandt and van Eyck.