Curtains, drapes of fabric suspended from rails or lines, have been around a long time, but have only recently become popular for providing an internal screen for windows. Although they have other purposes in paintings, they’re primarily used to conceal or to reveal when drawn back. Unusually, they can be depicted as part of the content of a picture, or added to it as a deception, a trompe l’oeil, to fool the viewer into thinking the curtain isn’t in the picture, but is real.

It was Raphael who was probably the first painter to attempt a trompe l’oeil using curtains, in his Sistine Madonna from 1512-13.

Now recognised as one of Raphael’s greatest and most important paintings, it was donated by Pope Julius II to the Benedictine basilica of San Sisto in Piacenza. The two saints shown are Saint Sixtus II and Saint Barbara, whose relics were preserved there. The Madonna and saints are painted superbly, but it’s the rest of the image that is most fascinating. The two cherubs with tousled hair at its foot are gentle touches of humour for a congregation as they looked at this image.

But Raphael’s visual feat is the curtains. He was by now confident that his realism was sufficient to pull off a trompe l’oeil, and fool the viewer into thinking that they were looking at a painting behind real curtains, at least until they got close. Having fooled them once, they’re now more receptive to the image beyond the curtains.

Those curtains also have theological significance: they mark the separation between the physical and spiritual worlds. As they are painted and not real, though, access through them is always open. No one can come along, draw them closed, and stop the ordinary person from accessing Christ. In a world where almost everything else, apart from air, was heavily controlled, this was and remains an empowering message.

Curtains are bold moves in some other religious paintings, including Oleksandr Murashko’s breathtaking Annunciation from 1907-08. Apparently, he was first inspired to paint this when he saw a girl part light curtains to enter his house from the terrace outside, and saw a parallel with the entry of the Archangel Gabriel in the Annunciation.

Their role in Dante Gabriel Rossetti’s Girlhood of Mary Virgin from 1848–9 is less convincing. This contains some archaic devices, such as the gilt and lettered halos, and an oddly-proportioned angel, but shows what Rossetti envisaged might have been the pictorial reality of the Virgin Mary during her youth. She works on embroidery with her mother, Saint Anne, while her father, Saint Joachim, prunes a vine. Those are shown realistically with an abundance of symbolic objects, but the curtains seem merely a background.

A curtain formed from an outsized handkerchief is concealing in Raphaelle Peale’s Venus Rising From the Sea – A Deception (c 1822). This was a visual criticism of the small-minded attitude to the display of paintings of nudes at the time.

With curtains concealing what shouldn’t be seen, they provide a means for the voyeur to peep through them.

The story of Susanna (or Shoshana) and the Elders is told in the Old Testament book of Daniel, chapter 13, and centres on voyeurism, blackmail, and justice. Susanna was a beautiful married woman who was bathing in her garden one afternoon, having dismissed her servants. Two lustful elders spied on her, and as she returned to her house they stopped her, and threatened that, unless she agreed to have sex with them, they would claim that she had met her lover in the garden. Being virtuous, Susanna refused their blackmail, and was promptly arrested, charged with promiscuity, and awaited her execution.

It was only after the intervention of the young prophet Daniel that the elders’ conspiracy was revealed, Susanna was acquitted of the charge, and the elders executed instead. Lovis Corinth’s early Susanna Bathing from 1890 adopts a traditional approach, where Susanna is seen in the flesh, being spied on by a peeping elder from behind a curtain.

Pedro Américo’s Faust and Gretchen from 1875-80 uses this in the context of the seduction of Gretchen in Goethe’s Faust. The shadowy figure of Mephistopheles is eavesdropping behind the curtain at the right, and white lilies, a symbol of her virginity, lie fallen on the floor.

While peeping is implicitly non-consensual and unwelcome, curtains can also be used for revelation.

One of Millais’ last paintings, before his death the following year, was Speak! Speak! (1895), which is also one of his most enigmatic. Millais’ son reported that this scene is set in ancient Rome. The young man had spent much of the night reading through the letters of his lost love. At dawn, the curtains were parted to reveal her, dressed for her bridal night, gazing upon him with sad but loving eyes. The title of the painting is therefore the words that he said to her spectre.

The mere presence of curtains denotes separation, particularly that between performers and their spectators.

Antoine Watteau adds a scarlet curtain both for colour and as the conventional separator between The Italian Comedians (1720) and their audience.

Ludwig Knaus shows the scene Behind the Curtain of a small itinerant circus in 1880. Performers were often colourful in both their costume and character, with many incongruities, such as the clown seen in the centre feeding a baby, and looking straight at the viewer. Their curtain is also rough and ready.

Grant Wood’s Parson Weems’s Fable from 1939 refers to Mason Locke Weems (1759-1825), who wrote the first biography of George Washington shortly after the latter’s death. This contains several apocryphal stories, including the legend of the cherry tree, which didn’t appear until its fifth edition.

According to this, when Washington was six, he was given custody of a hatchet, which he used to cut through the bark of a superb young English cherry tree. When this was discovered the next day, Washington’s father asked the boy if he knew who had killed the cherry tree, to which George Washington admitted his guilt, saying that he couldn’t tell a lie. His father was overjoyed at his son’s honesty. Sadly, the story is generally considered to be a fabrication.

Wood’s ingenious treatment places Parson Weems at the right, holding open a stage curtain, as if narrating the story to the viewer.

Across much of the temperate parts of the northern hemisphere, this is the wettest part of the year. It’s when puddles are everywhere, and what used to be firm ground turns into soft deep mud. Footpaths and bridleways become deep tracts of mud, impassable in anything but high boots. Yet look through paintings of winter and you’ll notice that few artists before 1800 have depicted people, vehicles or animals in mud of any significant depth. This weekend I look at some of the more faithful accounts of this ingloriously muddy time of year.

In the early nineteenth century, streets in major cities in Europe including Paris spent much of the winter as muddy morasses. Enterprising poorer inhabitants took long planks to locations where the more affluent would try to cross those rivers of mud, and hired them out to enable the rich to stay cleaner.

This is shown well in Louis-Léopold Boilly’s Passer Payez, or Pay to Pass, from about 1803, where a whole family is taking advantage of one of these crossings. This spared their footwear and clothing the otherwise inevitable coating of mud. As you can see, their shoes, lower legs and clothing are amazingly clean, as if they might actually have been painted in Boilly’s studio rather than the muddy streets of Paris.

As realism and real-world scenes became more popular in the middle of the nineteenth century, Adolph von Menzel showed a more accurate view of the problem of muddy roads in his Hussars Rescue a Polish Family from 1850. It had clearly been a wet autumn, with the leaves still burning red and gold on the trees in the background. These mounted soldiers are helping the elderly women from their carriage across the muddy ruts of the road. The hussar in the foreground, with his back to the viewer, even has mud on his riding boots.

One of the first artists to have used mud in a more meaningful way is Jean-Léon Gérôme, in his 1868 painting of The Death of Marshal Ney. Michel Ney (1769-1815) was a leading military commander during the French Revolutionary and Napoleonic Wars, and was made a Marshal of France by Napoleon. Following Napoleon’s defeat and exile in the summer of 1815, Ney was arrested, and tried for treason by the Chamber of Peers. He was found guilty, and executed by firing squad near the Luxembourg Gardens in Paris on 7 December 1815.

Gérôme shows Ney’s body abandoned after the execution, slumped face down and lifeless in the mud, his top hat resting apart at the right edge of the canvas. The firing squad is being marched off, to the left and into the distance. The mud only reinforces Gérôme’s powerful image of a cold, bleak, heartless execution.

Mud also has its recreational uses, as children of all eras will attest. Ludwig Knaus’s painting of Mud Pies from 1873 shows a group of children in the evening, near Dusseldorf, Germany, who are enjoying play in and with the mud, which is less fun for the swineherd behind them.

While other Impressionists had been exploring the effects of transient light on the River Thames, in 1875, Giuseppe De Nittis examined the city’s muddy and rutted streets, in his painting of The Victoria Embankment, London. This wasn’t one of the older roads in the city either: the Victoria Embankment wasn’t constructed until 1865, and had only opened to traffic five years before De Nittis painted it.

Muddy roads in northern British cities like Leeds were one of the favourite settings for the nocturnes of John Atkinson Grimshaw. At The Park Gate from 1878 (above) and November from 1879 (below) are glistening examples.

There’s an old English proverb “February fill dyke, be it black or be it white”, referring to the rain (black) or snow (white) that usually falls heavily during the month and fills all the ditches. Benjamin Williams Leader borrows that in his February Fill Dyke showing the waterlogged countryside near Worcester in 1881.

Mud became a favourite effect in the Naturalist paintings made so popular in France by Jules Bastien-Lepage.

Pas Mèche (Nothing Doing) (1882) shows a cheeky ploughboy equipped with his whip and horn, on his way out to work in the fields. His face is grubby, his clothing frayed, patched, and dirty, and his boots caked in mud.

But for real mud, deep enough for wheels and legs to sink in and cake clothing, I turn to central and eastern Europe.

Jakub Schikaneder’s The Sad Way from 1886 shows a single weary horse towing a cart on which a coffin rests. The woman, presumably widowed before her time, stares emptily at the rutted mud track, as a man walks beside them. It’s late autumn in a world that is barren, bleak, muddy and forlorn.

Józef Marian Chełmoński’s undated Market is one of the most vivid insights into country life in Poland during the late nineteenth and early twentieth centuries. To reach this street market, carts are being drawn through a deep ditch full of muddy water. Market stalls are mounted on tables set in the mud, which forms the basis for everything.

Also undated is contemporary and fellow Polish artist Alfred Wierusz-Kowalski’s Meeting the Train. A couple of horse-drawn carts have gone to a rural railway station to meet a train. The winter snow still covers much of the ground, except where it has been turned into rutted mud on the road.