With artists’ colourmen supplying growing ranges of ready-made oil paints in bladders, it was relatively straightforward for landscape painters like John Constable (1776-1837) to go out in front of the motif and paint en plein air in oils. Neither were artists like Constable reliant on the support of a team of craftsmen in their own workshops, as they could buy canvases stretched and primed, ready to paint with those prepared paints.

It is a tribute to the skills of the colourmen, and those of the painter, that so many oil sketches survive today, despite in many cases being painted on ephemeral materials such as paper and cardboard.

But it was Constable’s rival, Joseph Mallord William Turner (1775–1851), who was the more technically innovative. Trained in classical techniques of oil painting at the Royal Academy Schools in London, one of the benefits brought by Sir Joshua Reynolds, Turner’s oil paintings should have been constructed to last longer than Rembrandt’s.

In the autumn of 2014, when London hosted a unique coincidence of exhibitions of the late works of both Rembrandt and Turner (at the National Gallery and Tate Britain, respectively), it was easy to make comparison between the condition of their paintings. In general, Rembrandt’s more experimental works appear in good condition although now approaching four hundred years old, and are often much better than the more troubled paint layers on Turner’s canvases, which are two hundred years younger.

Unlike Constable, who sketched largely in oils, Turner was probably the most accomplished watercolourist of the century (possibly of all time), and appeared quite happy to paint the great majority of his plein air sketches using non-oil media. He was extremely innovative in both oils and watercolours, always keen to push the bounds of technique in pursuit of his art.

For example, Turner’s Seapiece with fishing boats off a wooden pier, a gale coming in (date not known, possibly c 1801) has extensive use of sgraffito, which may have been made using a knife, brush handle, or even his fingernails.

For the duration of Turner’s career until 1829, his father worked as his studio assistant, stretching and priming his canvases in particular. Thereafter, following his father’s death, Turner had to rely on the primed panels and canvases which he could purchase from colourmen. His techniques also became increasingly radical, and some of his choices of materials were not as wise as they could have been. As a result, rising proportions of his paintings have suffered problems.

As with many of Turner’s paintings, his Story of Apollo and Daphne (1837) has extensive use of paint based on drying oil and lead white. This was not in some misguided attempt to recreate the appearance of old Masters (unlike Reynolds), but in Turner’s remarkable exploration of the combination of colour contrasts and texture. Although not readily visible here, they also brought rapid changes during drying, and commonly serious problems with cracking, even when applied to wood panels, as here.

The techniques, their success and failure are shown well in one of Turner’s most famous paintings on canvas, The Fighting Temeraire tugged to her last Berth to be broken up (1839).

Turner applied high chroma paint quite thickly on top of already thick and layered paint. Although this produces breathtaking effects, as shown in this detail, it will result in problems with cracking unless those superficial layers dry more slowly than layers underneath, a phenomenon embodied in the ‘fat over lean’ rule. Here they have clearly not done so, and that has resulted in patchy areas of cracking.

Some areas are worse affected, with apparent wrinkling probably resulting from the slumping of impasto, and undried paint exuding. Here this is most probably the result of Turner’s use of bitumen or asphalt, which inhibits the oxidative ‘drying’ of linseed oil, and commonly leads to problems in the paint layer. Sadly bitumen was a popular pigment in the 1800s, although its adverse effects were well known.

Turner’s The Rape of Proserpine (1839), another work on canvas, also has its problems. Here Turner worked freely, mixing layers of low to medium impasto with thinner glazes and scumbles, particularly in the sky. Although cracking has occurred, this has not resulted in significant loss of the paint layer.

Problems in the foreground, and middleground, are rather worse, where it is thought that bitumen has been used. Cracks here have widened, and become filled with paint which has risen from deeper layers.

Some of these changes had taken many years to become manifest, but Turner and his contemporaries were well aware of the problems in some of his paintings. In the case of The Opening of the Wallhalla, 1842 (1843), which was painted on mahogany, Ruskin reported that it had “cracked before it had been eight days in the Academy Rooms”, although this overall view shows little evidence of that damage.

Hellen and Townsend attribute this to Turner’s extensive use of Megilp, here a product sold by his colourman containing leaded drying oil and mastic varnish. Used sparingly and with great caution, such medium modifiers do not necessarily cause serious ill-effects. But Turner has used Megilp to excess, to produce a soft impasto used in the foreground figures, in particular. These have resulted in wide and shallow drying cracks, as the surface has dried quickly and shrunk over trapped layers of liquid paint.

Turner’s Approach to Venice (1844) was painted with very thin transparent glazes over thick white impasto, which creates a distinctive flickering effect in highlights.

Despite Turner’s efforts to get the white impasto to dry more quickly, the glazes dried first, and cracked as they became stressed over the white which was still wet. This has not been helped by the later conservation process of lining, which places an additional layer on the back of the canvas to help the support do its job.

Turner’s The Visit to the Tomb (1850) is one of four canvases which he completed not long before his death, forming a series telling the story from Virgil’s Aeneid of Dido and Aeneas in Carthage. Three of these are known today, all in the Turner Bequest at the Tate Gallery, where their conservation is an ongoing task.

Turner apparently worked on these together, as a group, first sketching in thin warm and cool layers appropriate to each work’s theme. Over those, various thick and thin layers were applied, often containing beeswax as a thickener, medium modifiers such as Megilp and its variants, siccatives, and some mastic resins. Sadly their startling appearance when first exhibited did not last long, and has changed a great deal since.

Turner’s devotion to visual effect has unfortunately compromised his oil paintings in respect one of the most compelling reason for using oil paint in the first place: its longevity. Ironically, many of his watercolours have survived the years rather better.

JMW Turner was also one of the first painters to make use of the latest pigments, including chrome yellow, which he purchased in tubes rather than bladders. It was John Goffe Rand who patented what he termed “metal rolls for paint” in 1841. At first, these were seen not so much as a means of increasing the portability of oil paints, but for their cleanliness and lack of odour.

Adoption among professional painters at the time was patchy: these new tubes were expensive, and required filling equipment which many of the existing colourmen did not see was necessary. Oil paint continued to be sold in bladders for several decades afterwards, although newer pigments offered by the larger and more innovative colourmen often only came in tubes. Slightly later, some colourmen utilised another recent invention by John Landis Mason in 1858, the screw-top jar, although those never proved as popular.

By now the old craft-dominated workshops were becoming increasingly rare, replaced by the studio, as shown in John Ferguson Weir’s An Artist’s Studio (1864).

Wooden ‘pochade’ boxes which had been used by painters who worked en plein air could now contain a dozen tubes of oil paint, rather than bladders, as Carl Reichert shows in his witty Der Malerstreit (The Painters’ Dispute) (1903).

They could also be coupled with a lightweight portable easel and canvas-carrier, as in Hans Andersen Brendekilde’s L.A. Ring Paints with Aasum Smedje (1893).

Outdoor painting was inevitably direct, or alla prima; there was no time for painting in layers, other than a thin underdrawing perhaps. Its enthusiastic adoption by the Impressionists led to the next change in technique: the displacement of traditional layers by alla prima, as epitomised in Claude Monet’s Le bateau atelier (The Studio Boat) (1876).

References:

Callen A (2015) The Work of Art. Plein Air Painting and Artistic Identity in Nineteenth-Century France, Reaktion Books. ISBN 978 1 78023 3555 0.
Clarke M (2015) Precursors of Plein Air Painting, pp 59-80 in Greub S (ed) Monet. Lost in Translation, Hirmer. ISBN 978 3 7774 2428 6.
Hellen R & Townsend JH (2014) Materials, Technique and Condition in Turner’s Later Paintings, in Brown DB, Concannon A & Smiles S (eds) Late Turner, Painting Set Free, Tate Publishing. ISBN 978 1 84976 145 1.