Of all the Impressionists and Post-Impressionists, it is surely Paul Cézanne (1839-1906) who is the most enigmatic. During the twentieth century, his paintings were claimed by almost every new modernist style, from Cubism to abstract art, as its precursor. Whole books have been devoted to trying to explain how he ‘projected’ views onto his canvases, their complexity and frequent exceptions only serving to cast doubt on that approach altogether.

In this article, I’m going to look at some of the evidence in his oil paintings as to how he made landscapes during the later part of his career when he was working in the countryside around his home in Aix-en-Provence.

Cézanne learned to paint landscapes in the north, when he worked alongside other Impressionists when they were painting in front of the motif. Among the most important influences on his Impressionist style was Camille Pissarro, who even then was known for his ability to paint en plein air very briskly.

For Cézanne, painting outdoors was protracted rather than sketchy. At first, this caused him problems when he completed different passages in a view with their shadows. This view of The House of Père Lacroix, Auvers-sur-Oise, painted in 1873, shows this well, as his shadows indicate that different sections of the roof were painted several hours apart.

As shown in the marked-up image below, the angles subtended by the shadows are not consistent. In some, the sun is high in the sky, close to its zenith, but in others rather lower. These indicate a wide range of solar elevations, and the passage of a considerable period of time. This matches contemporary accounts of his plein air painting technique.

Towards the end of his Impressionist period, he started to organise the way in which he applied paint with his brush. What is unique about this, dubbed his constructive stroke, is that those brushstrokes appear independent of the underlying form. This is quite unlike Vincent van Gogh’s brushstrokes which swirled with the form of his cypresses, for example.

One of his earliest paintings to show his constructive stroke is The Bridge at Maincy, which he painted in 1879-80. Much of the foliage of the trees has here been formed using diagonal strokes of the brush, which assemble into irregular patches. Within each of those, the range of colours is relatively limited.

These Poplars, also from 1879-80, show extensive use of this technique, with most of the strokes used for the foliage of the poplars being diagonal, at approximately 45˚, irrespective of the underlying form. This gives these canopies a very solid appearance, which is only loosely reflective of the underlying anatomy of the tree. He has also reduced the range of tones and colours used in the trees, and there is no aerial perspective.

In his later paintings in the south of France, Cézanne used a richer range of brushstrokes. Here, much of the foliage and other greenery is built using a modification of the constructive stroke, which seems to follow the underlying form more closely. Fields and the rocks in the foreground are formed more conventionally. With its thinly applied paint, this work affords a valuable glimpse or two of his underlying drawing, for example in the skyline.

Pigment analysis has shown that the greens here are a mixture of emerald green and viridian, which is known to have been one of Cézanne’s favourite colours. But in the foreground, at the edge of the path, he has built the colour in layers, with lead white mixed with viridian, over which Cézanne applied a yellow lake glaze. The use of such glaze layers is unusual in what is normally assumed to be direct painting, and shows that the artist left the foreground paint to dry for a week or more before applying that layer, almost certainly in the studio.

In many of Cézanne’s paintings after 1890, his constructive strokes became more prominent and start to dominate the structure of whole work. In Large Pine and Red Earth (1890–5) they are used throughout the foreground foliage and vegetation, and even start to appear in some patches on the trunk. Note that their prevailing orientation has also changed, from roughly 45˚ to near-vertical, particularly in the patches of colour in the foreground.

Cézanne’s Le Lac d’Annecy is generally taken as the inception of his most radical style and approach to painting, although it is one work from this period in which constructive strokes are least prominent.

In the searing light of Provence, Cézanne’s paintings have a lighter tone, and start to develop areas which are left unpainted altogether. These resemble watercolours rather than oils, with outlines drawn in using a dark ultramarine blue and small patches of less prominent constructive strokes.

Cézanne’s most unusual paintings are his late watercolour landscapes, such as his Almond Trees in Provence (1900). These have no parallel among his works in oils, and typically have very large areas of reserved space, with selected forms such as the almond trees here painted using flares of concentrated colour.

Below is his House at the Edge of the Water, showing a similar approach from 1900-04.

More typical of his late oil paintings is Forest Scene (Path from Mas Jolie to Château Noir) from 1900-02, below, which is built almost entirely of constructive strokes, with a few sketchy outlines to indicate the form of the trees and some of the steps.

In the twentieth century, it was claimed that Cézanne’s constructive strokes were a direct precedent to Cubism and abstract art. This painting, at least, appears to be thoroughly representational, and was almost certainly painted mostly in front of the motif.

Looking more closely at this detail, it’s clear that there’s no underdrawing, abundant areas which haven’t been painted, and that paint has been applied wet on dry.

Instead of his earlier pencil or charcoal drawing, Cézanne has drawn in outlines of the trees and the top of the steps using a fine brush with dark blue and black paint. As these have been painted over in parts, some of those lines at least have dried before the last paint was applied. Where his original line has been overpainted, Cézanne has in places added further lines later.

Many of the patches of colour built using constructive strokes are uniform in colour throughout that block of strokes. In places, they too have been superimposed on a dry lower layer of paint, although in some places fresh paint has been applied on wet paint, and the colours have mixed.

This work appears to have been the product of a series of sessions of painting, spread over a period of a week or more, during which Cézanne has methodically worked on different passages to create a complex paint layer.

It’s often claimed that Cézanne’s late landscapes lack conventional visual cues to depth, and that he didn’t use 3D perspective projection.

His Banks of a River from 1904 could easily be interpreted as verging on the abstract. Looking more carefully, he shows depth recession in the patches of colour formed by his constructive strokes, and there is more than a touch of aerial perspective too. Even the sky is here built up of patches of stroked colours.

Overlapping patches here also show his use of wet-on-wet and wet-on-dry, confirming that this painting was completed over a period of at least a week or two, and not in a single plein air session.

Careful examination of Cézanne’s paintings shows that even a few months before his death, at least some of his paintings largely adhere to the conventions of modern perspective projection, as seen in his Le Cabanon de Jourdan (1906), above and below.

Cézanne’s paintings remain enigmatic. The artist himself gave us few clues as to what his intentions were, the paintings themselves can’t readily be compared with anything else, and most twentieth century accounts conflict with what Cézanne actually did. Perhaps it’s better to take them for what they are.