Medium and Message: Oil on paper
Centuries of experience with painting using oil paints have proved the importance of a robust support and a ground that isolates the paint layer from its support. Older use of wood panels with a gesso ground consisting largely of gypsum or chalk ensured the paint layer wouldn’t be subjected to mechanical stress, and would remain isolated from the underlying wood. Canvases became popular because of their relative lightness particularly in larger sizes, but still require an isolating ground layer both to protect the canvas from damage by the paint, and to prevent discolouration of the paint.
When sketching in oils in front of the motif became increasingly popular in the late eighteenth century, those paintings weren’t intended for public view, but as an aid for the artist when composing finished paintings in the studio. Rather than gather hundreds of small oil sketched on canvas or panels, the first plein air painters usually used paper or cardboard as support and ground. Subsequently, when their studios were sold off following their death, surviving oil sketches were usually laid on canvas for preservation and display.

Although he probably wasn’t the first to compile a library of oil sketches, those gathered by Pierre-Henri de Valenciennes when he was painting in the Roman Campagna in the 1780s are among the most brilliant. This untitled view of the countryside near Rome is thought to have been painted in about 1783.

At about the same time, the Welsh painter Thomas Jones was doing the same thing in and around Naples as well. This tiny view of A Wall in Naples was painted in about 1782, and is now one of the gems in London’s National Gallery. Below is a detail.


Jones was taught by the Welsh artist Richard Wilson, but none of his oil sketches have survived. Jones’ Capella Nuova outside the Porta di Chiaja, Naples is another example that’s significantly larger, and now in the Tate Gallery.

Valenciennes went on to assemble a large library of his oil sketches that he used for his studio paintings following his return to Paris. He was admitted to the Academy in 1787, published an influential manual of perspective and painting in 1799, and became Professor of Perspective at l’École des Beaux-Arts in Paris in 1812.
Among the aspiring young landscape painters who followed in the footsteps of Valenciennes was Camille Corot, who was taught by Achille Etna Michallon, who in turn had been taught by Valenciennes. Corot painted in the Roman Campagna between 1825-28, using the same techniques of applying his oil paint direct to sheets of paper.

Corot painted this View of Rome: The Bridge and Castel Sant’Angelo with the Cupola of St. Peter’s in 1826-27. This is one of the best-known bridges over the River Tiber, and not far from the centre of the city. The view is taken from the north-east of the bridge, on the ‘left’ bank, probably close to the Piazza di Ponte Umberto I, looking towards the south-west (‘right’ bank). The painting is sketchy rather than finely finished, and appears to have been painted en plein air onto a sheet of paper that has subsequently been laid on canvas.

This View of the Convent of S. Onofrio on the Janiculum, Rome is another from Corot’s first campaign in Rome.

Corot’s years in Italy were formative in his own development, and one of the key elements he put in place to hand on to Camille Pissarro and other Impressionists. The Bridge at Narni is one of his finest oil sketches.

Others followed Valenciennes’ instructions, among them Carl Blechen, a brilliant German landscape painter who sketched the Tiberius Rocks, Capri during a visit in 1828-29, again on paper.

Blechen’s late oil sketch of A Scaffold in a Storm was painted in about 1835, shortly before he succumbed to severe depression. This anticipates many elements of Impressionism: it appears to have been executed rapidly in front of the motif (although a view from his studio over Berlin and Brandenburg), with many brush-strokes plainly visible; details are composed of stylised marks; it is an everyday if not banal subject, with an informal composition.
However, the French Impressionists seldom if ever sketched in oils on paper, as their paintings made in front of the motif were intended to be sold to and viewed by the public, for which paper wasn’t considered suitable. Times had changed.






















