Joshua Reynolds (1723–1792) received his first instruction in painting between 1740 and 1743, during an apprenticeship with Thomas Hudson (1701–1779). During this time, he would quickly have become familiar with the economical and systematic painting technique used in the studio, along with the use of stock poses and drapery painters.
Yet this formula was one from which he himself increasingly diverged, particularly after his trip to Italy between 1749 and 1752. To get a stronger sense of the characteristics of his own practice, it will be helpful to look at his approaches to the different stages of a painting’s production.
By the mid-18th century, pre-stretched canvases were readily available from artists’ colourmen in a range of standard sizes. It seems certain that Reynolds bought most of his canvases pre-prepared with a priming, although he sometimes used a bare or un-primed canvas.
On a few occasions, Reynolds utilised wooden panels. The portrait of Mrs Jane Braddyll (died 1819) has a support made of four horizontal oak boards, adhered together with animal glue.
Reynolds generally was not economical with his use of paint and cross-section samples taken from his paintings often reveal thick, many-layered structures.
Reynolds built up rich and substantial surfaces using numerous layers of paint and glazes, striving to imitate the translucent appearance of aged oil paint and rich glazes that he observed in the work of the old masters.
A sample taken from the clouded sky in the portrait of Mrs Mary Nesbitt (1743–1825) shows several red and brown under-layers, over which the sky and clouds were painted in Prussian blue, followed by a warm coloured final glaze, containing red and yellow pigments.
Over his career Reynolds became a masterful handler of paint. Vigorous, textured brush marks are frequently visible in thick passages of paint and testify to his often-dynamic painting style.
The sleeve of Miss Jane Bowles’s dress was depicted with thickly brushed cream coloured paint. While this was still wet, a small amount of grey paint was worked into the surface in a wavy stroke, and finally liquid brown and yellow paint was applied over this in thin zigzags to complete the design.
Reynolds frequently used stiff paint, laid on in swift brushstrokes, to produce textured effects and broken lines. The golden rays of light that pass through a gap between the trees in the portrait of Miss Jane Bowles were created by applying a small amount of yellow paint in quick strokes. The paint has skipped across the tops of the canvas weave, giving the effect of dappled sun.
Reynolds was never completely settled in his use of pigments and tried many different ways of combining colours. He also experimented with new pigments as they became available.
The colour ‘patent yellow’ was registered in England in 1781 and this pigment was found in a sample taken from the foreground in the portrait of Mrs Robinson, painted only a few years later in 1784.
Perhaps the most infamous problem of Reynolds’s painting technique is the fading of the flesh paint in his portraits. The pigment responsible for this loss of colour is a red lake or Carmine. For a period, Reynolds coloured his flesh tones using lake pigments.
The face of the Duke of Queensberry from 1759 has faded significantly because of the use of red lake pigment. Once it became apparent that his portraits were often beginning to fade, Reynolds adapted his technique, turning instead to vermilion and red lead pigments.
The carnation on the cheek of Mrs Mary Robinson from 1784 still has a strong pink colour and must have been coloured with the same vermilion used to paint the red bow on her dress.
Bitumen has often been blamed for much of the cracking and the ‘alligator-skin’ like appearance of the surface in Reynolds’s paintings. Oil paint containing bitumen never fully dries and so it can cause wrinkling and cracking of a paint film.
However, analysis suggests that extensive layering, sometimes of incompatible materials, seems more often to have been the significant factor in the cracking and drying defects in his paintings, rather than the behaviour of the individual pigments and binders alone.
Reynolds did use a range of binding media, but in the majority of his paints he used conventional drying oils. Even so, he almost always modified his paint mixture with other materials, most commonly by adding a proportion of a natural resin or varnish.
Unfortunately, the addition of resin also made the paint more prone to cracking. Reynolds is also known to have experimented with wax. Samples taken from this portrait of Miss Jane Bowles (1739–1810) revealed that he applied a coating of beeswax before finally glazing areas of the painting.
It is unfortunate that Reynolds, by striving to imitate the qualities he admired in the aged oil paintings of the old masters, doomed so many of his paintings to survive as the faded, darkened and cracked relics we see today.
Nevertheless, the best preserved of his paintings attest to the qualities that so captivated his contemporaries: the effects of light and shade, and their interplay; harmonious colouring; and a deep richness of tone and lively texture.
Text adapted by Dr Alexandra Gent, Paintings Conservator at the National Portrait Gallery, from Gent, A., 'Reynolds, Paint and Painting: A Technical Analysis', in Davis, L., and M. Hallett, Joshua Reynolds. Experiments in Paint, London, 2015, pp. 42–53.