There’s huge variation in the time it has taken for artists to create their paintings. These range from a few minutes, well under an hour, to years. This article looks at some contrasting examples, and considers the merits of painting fast or painting slow.

Historically, when the area to be painted is taken into account, painting buon fresco demands greatest speed, although because of the sheer size of many frescoes, completing major works like the ceiling of the Sistine Chapel took Michelangelo several years. My example is a work of more modest scale, Masaccio’s Holy Trinity in the Basilica of Santa Maria Novella in Florence.

Because buon fresco is painted into fresh, wet plaster, the artist can only plaster and paint a certain area each day – known in Italian as the giornata, a day’s work. The first stage would have been completed by assistants, who laid a rough underlayer of plaster known as the arriccio over the whole wall, and left it to dry for several days.

Once that had dried completely, Masaccio and his assistants transferred their drawings onto the surface of the arriccio. This may have been performed by scaling up from the squared drawing and painting using a red pigment sinopia, or full-size drawings may have been pricked to make holes in the paper and a bag of soot banged against that paper when held against the wall – a technique known as pouncing. Masaccio is known to have used both techniques, and may well have used each in different sections of this work.

On each day of painting, assistants would prepare the colours by mixing pigments in water. That day’s supply of plaster, the intonaco (meaning plaster), is then prepared by mixing water with lime. That day’s giornata is covered with a thin layer of intonaco, and about an hour later Masaccio started painting into it. He then had about eight hours before the intonaco dried and he could apply no more fresh paint.

Like many of the best fresco painters, Masaccio extended his painting time by using paint mixed with milk or casein and a little lime – effectively a lime-based casein paint – which could be laid onto dry intonaco.

The geometric requirements of this painting also merited special measures. When the intonaco was first applied, it was marked to indicate key construction lines, such as those in the barrel-vaulted ceiling, and down the pillars at the side. The remains of these incised lines are still visible when the fresco is viewed in raking light. In this case, there is evidence that Masaccio used lengths of string attached to a nail sunk at the vanishing point of the linear projection, below the base of the cross.

During the conservation work and movement of Masaccio’s painting in the 1950s, the opportunity was taken to study its construction. Leonetto Tintori drew up a plan of all the identified construction lines and edges of giornate; I have sketched in the latter from a reproduction of a drawing made at that time, which has since been destroyed.

It’s estimated that the whole painting would have required some 24 giornate, although because of the long history of damage and attempts at its restoration, that number must remain flexible. Assuming that Masaccio painted six days a week, that would have required a minimum of four weeks working for at least ten hours each day. Fresco painting doesn’t permit easy alterations: if any repainting was required and couldn’t be accomplished using dry technique, that day’s giornata would have to be removed, replaced and repainted.

Sketching with oil paints in front of the motif is far simpler, and on a more modest scale. Because of constantly changing light and shadow, most proficient landscape artists aim to complete their oil sketches in under two hours, and an hour is ideal.

Robert Henri’s Landscape Sketch at Escorial (1906) was painted on a wooden pochade panel, almost certainly in a single short session outside the city of Madrid, in the hills near the Escorial.

The young Canadian artist Tom Thomson excelled in rapid sketching in oils, with several witnessed accounts of him dashing off a painting in little more than fifteen minutes. As a result he was able to capture many transient effects, such as the passing thunderstorm in Thunderhead from 1912-13.

Prior to the nineteenth century, quick oil sketches were almost never shown to be public, but used by masters including Valenciennes and Constable purely as preparative studies. When fashions changed, it became acceptable if not desirable for paintings to look sketchy and rushed. Sometimes appearances can be deceptive.

On the morning of 31 August 1927, the maids working in a manorhouse close to Edvard Munch’s studio were using an electric vacuum cleaner when fire broke out in that room. The maids and occupants of the house fled. Munch and other neighbours helped the owners rescue many of their possessions. The local fire brigade attended promptly, and the fire was soon brought under control. It was claimed that Munch set his easel up during the fire, and painted The House is Burning! (1927) there and then.

After careful research, though, it turns out that Munch’s painting is almost certainly based on a photograph published in a newspaper the following day, which was carefully recomposed and augmented to heighten its drama.

Some masters of fast painting used those skills in multiple sessions, to increase the amount of detail they could incorporate into a landscape. When Pissarro suffered from eye problems late in his career, he painted from rooms with views over the streets of Paris, and produced some of his finest cityscapes.

Boulevard Montmartre, Spring Morning (1897) is composed primarily of buildings and streets, a plethora of figures, and countless carriages to move those people around – the ingredients for so many of his late paintings.

In the foreground, Pissarro may have formed each quite roughly, but he has painted in sufficient detail. Three white horses range in tone and colour, with highlights on the front of each head. You can see which people are wearing hats, and spot ladies in their fashionable clothing.

Deeper into the distance, detail is lost, and the carriages and crowds merge into one another. Still they have a rhythm, highlights and shadows, and form. He must have spent day after day at his hotel window populating these busy streets.

Other Impressionist paintings appear at first sight to have been painted quickly in front of the motif, but were worked on over a period of months in the studio.

The myth about Monet’s Grainstacks series is that they depict transient effects of season, weather, and light, as they were painted en plein air over the course of the winter. Looking at all twenty-five, I have long had my doubts, and suspected that Monet spent a lot of the time prior to their exhibition making further changes to them, which couldn’t therefore have been en plein air nor even faithful accounts of each motif at the moment they depict. This in no way lessens Monet’s sublime achievement, nor their art in any way. It’s just that they aren’t quite the paintings described by the myth which has grown around them.

Looking at Grainstacks, End of Summer, considered to be one of the earliest in the series and numbered 1266, the trees behind the two grainstacks are still in full summer leaf, with no indication of the advent of autumn. Yet Monet’s signature gives the year as 1891. Looking at its paint surface in detail (below), some has been applied wet-in-wet and blended with underlying and adjacent paint, but many other brushstrokes have clearly been applied over dry underlayers.

The blue-grey shadow of this grainstack was applied with relatively dilute paint wet-on-dry over thicker off-white paint which has marked surface texture. However, that off-white paint has itself been applied wet-on-dry over a pale green layer. This couldn’t have been achieved in the same day, even when the ambient temperature was warmer during the early autumn, but probably reflects at least three sessions with drying time in between them.

Slow drying of oil paints leaves them ‘open’ to reworking for many days or weeks after the paint has been applied. Other media, such as egg tempera, are quite the opposite, and dry and start hardening within minutes. Traditional egg tempera technique thus applies very small strokes with fine brushes, painstakingly building up the paint layer one stroke at a time.

The Wilton Diptych was painted on two small panels of oak wood using egg tempera, in a workshop which was clearly very experienced at making such works. Each panel is made of one wider board and a narrower strip. The two parts of a panel were joined by a craftsman using simple butt joints and were glued together with such care that the joins are almost invisible. They started off about 2.5 cm (1 inch) thick, and were then carved down to form an integral frame with a recessed painting surface.

The two panels are hinged together using gilded iron fittings, so that the completed diptych could be folded shut for portability.

To prepare the panels for painting, the bare wood was first covered with a thin layer of parchment, then over that a single layer of gesso was applied. This was composed, as was traditional, of natural chalk and animal-derived glue. The gesso extended over the frame mouldings to prepare them for gilding.

The fine brushstrokes are visible over six hundred years later, and details in the gilding also reflect what must have been many months of sustained precision craftsmanship in production.

The nineteenth century not only brought fast sketches, but a return to more protracted methods, illustrated well in John Everett Millais’ Ophelia, which he painted over 1851-52.

In early June 1851, Millais ordered the canvas on its stretcher, which came already primed with three layers of oil ground, consisting of lead white oil paint with white extenders of chalk, barium sulphate and china clay. On top of this is a further layer of ground which contains a mixture of zinc white and lead white, applied after the canvas had been stretched, presumably before its delivery.

Millais made quite extensive and partly scribbled drawings onto the ground before starting to paint the background en plein air in July. He chose a site in Surrey, on the bank of the Hogsmill River, between Ewell and Kingston, where the land is flat and the ground wet, even in summer. At that time of year, there are usually many biting flies or midges, and these troubled the artist during his eleven-hour working days. He apparently painted under an umbrella, and may have worn a ‘midge net’ to protect his face from being bitten.

During this phase, William Holman Hunt was painting close by. The pair had gone to prospect for suitable sites near Ewell in late June: Millais for Ophelia, Hunt for The Hireling Shepherd (1851-52), and both completed the landscape phase of their paintings by the end of October.

The Pre-Raphaelite principle of painting in front of the motif paralleled movements in France such as the Barbizon School and Impressionism, but with one major difference: Pre-Raphaelites painted in painstaking detail, demanding prolonged and protracted work outdoors, to the point where such detailed paintings became almost impractical.

One puzzle with this painting is its apparent lack of flies in the paint layer. If you have ever tried painting en plein air under constant fly attack, you will understand that midges and other flies are attracted by the odour of oil paint, and usually become embedded in wet paint in large numbers. Yet I haven’t seen any remarks made following close examination of Ophelia that there are the bodies of flies in the paint, nor the marks made by the artist trying to remove them from the wet paint.

Although Millais is claimed to have started work on the figure in late January 1852, by which time the landscape would have been dry to the touch, he didn’t purchase the dress worn in the finished painting until March.

Millais’ model for the figure of Ophelia was Elizabeth ‘Lizzie’ Siddall (1829–1862), one of the Pre-Raphaelite women who tragically died only a decade later from an opium overdose, after Rossetti taught her to paint and married her. An experienced model for several artists of the day, this time she was challenged in her work. Apparently from late January until March, each day she lay in a bath of tepid water, heated from underneath by lamps. It’s famously reported that one day the lamps failed, she became chilled, developed a cold, and had to receive medical attention. Her father threatened Millais with legal action to recover the costs of that medical aid.

Perhaps the greatest challenge, more than the midges of summer or long tepid baths, were the flowers. The painting features elaborate references to the symbolic meaning of flowers, while being constrained to species which occurred in Surrey. These include: roses as a symbol of love; willow, nettle and daisy for forsaken love, suffering, and innocence; pansies for love in vain; violets for faithfulness, chastity, or a premature death; poppies for death; finally forget-me-nots for remembrance.

Many of these would have been in flower when Millais was painting outdoors in the summer, but those which adorn the figure of Ophelia would have presented a problem, as at that stage all the painting had there was the white space reserved for the figure. It’s not clear how Millais solved this. It is apparent, though, from the detail above that he superimposed zinc white to make the decoration in the dress sparkle.

Millais still wasn’t fully satisfied, and in 1873, over twenty years after it had been exhibited, he made some additions and alterations to some of its lush vegetation and the figure’s face.

Pre-Raphaelite landscape painting was just as demanding, as shown by John Brett’s breathtaking view of Florence from Bellosguardo.

This was probably started in January 1863, without the help of significant preparatory studies, and painted entirely from the motif. Even with Brett’s apparent eye for fine detail at a distance, much of it must have been painted with the aid of a telescope, and it has been suggested that he may also have used a camera lucida and/or photographs. Regardless of how he managed to paint such great detail, it is a triumph of painting, both technically and artistically, and it came as a shock when it was rejected by the Royal Academy three months later.

It was the late nineteenth century, though, which brought the most painfully slow painting technique, that of Divisionism, in which the artist spent many months applying tiny dots or marks to the canvas to achieve ‘optical mixing’ of colour.

Georges Seurat painted his Divisionist masterwork La Grande Jatte in three phases totalling more than eighteen months. In the first, the dots he applied were mixed from available and fairly conventional pigments, including duller earths. In the second phase, he used a limited number of brighter and higher chroma pigments. In the third and final phase he added coloured borders which are distinctive of his paintings.

For artists, the bottom line is whether their funding can survive painting slow, or whether they have to paint fast to pay the bills and feed their family. Sadly, the Pre-Raphaelites and Divisionists discovered that the economics of painting slow didn’t work at all well. You may also recall Picasso’s famous demonstration that in a few minutes he could create a painting which, with the addition of his signature, would have kept Pissarro and Brett alive and well for several years.