British folk at the Tate: Art – but no class

"For many people, folk is a four-letter word," writes Jeff McMillan, co-curator of a new exhibition, British Folk Art, which opens today at Tate Britain. Why would this seemingly innocuous art form – associated with embroidery, pottery, and basket-weaving – be labelled an obscenity?

The answer lies in its status outside the mainstream. When the Royal Academy was founded in 1769, it was decided that a distinction should be made between high art and low craft: "No needlework, artificial flowers, cut paper, or any such baubles should be admitted." Folk art is aligned with the domestic, the raw, the artisanal – it was derided as "women's work," or the hobby of sailors killing time on ships. As such, folk art expresses the creativity of those excluded from elite high culture.

Like "outsider" art, which has become fashionable over the past decade, folk art is considered "naïve"; its practitioners are largely unschooled. The contemporary art world leans so heavily on theory and irony – it seems inevitable that the "authentic" would soon be fetishised.

Folk art is subversive; it is social history, told from the margins. However, it can easily be defanged and used to idealise a timeless British past, wherein class conflict doesn't exist. The link between social status and folk art is suggested in this exhibition, but not in a systematic way. It is not made clear enough.

Rather, there is an odds-and-ends collection of objects which are reduced to little more than curios for lack of sufficient political context. They appear more like the miscellaneous props of a BBC period-drama store cupboard than an earnest search through our history for art forms that have been overlooked. This is a shame.

While outsider art is practised by individuals, often socially isolated and removed from the centres of the art world, expressing a visionary inner life, folk art is more about communities and tradition, albeit reinvented according to individual whims. The objects on display here were largely sourced from regional museums; they range from ship figureheads to painting to papier-mâché meat which once adorned the shop window of a butcher's, from the 18th century to the mid-20th century.

The exhibition is organised according to different territories – sea, land, and city – which detracts from the power of individual objects and serves to create an aesthetic mood rather than a social history. However, there are some fascinating objects, which speak for themselves. They evoke the injustice of the industrial revolution, the rise of empire, and the process by which our society and the rest of the world was conquered by globalisation.

There are early advertising signs in the first gallery – visual symbols without words which were hung outside shops prior to the spread of literacy. Many are self-explanatory and unremarkable – a large wooden padlock to indicate a locksmith's, for example. More intriguing are the three large gold balls that once hung outside a pawnbrokers. Their design is borrowed from the coat of arms of the wealthy Italian Medici family, which absurdly added a dose of Renaissance grandeur to the sad act of having to pawn your wedding ring.

They are followed by non-descript embroidered images of ships, more signs, more objects that appear mundane instead of magical. Perhaps the most interesting assemblage in the exhibition can be seen in a glass showcase in the second gallery.

Poignantly, there is a blackened wood figure of a chimney sweep, about the size of a small child. His face does not suggest a child, however, but a wizened man. He looks solemn. The statue was a shop sign – perhaps it represents an attempt to deny the exploitation of children that was a feature of the trade during the industrial revolution. Boys as young as four were sent up chimneys and risked falling, suffocating, or burning to death. In 1840, the government banned the use of children, but the law was largely ignored.

Another highlight is the series of four gods-in-a-bottle; they are carved religious icons contained within glass bottles, emptied of whisky or medicine. One contains a delicately made ladder, leaning against a large crucifix, inviting religious ascension. The god-in-a-bottle was far less common than the ship-in-the-bottle and was associated with the Irish Roman Catholic diaspora, in pursuit of work in the mining and construction industries in the north of England in the 19th century. They may have been used as talismanic objects; they are eerie and beautiful.

Also notable is a small oil painting of a "champion rat-catcher," from around 1840. It shows a black dog in a pit mauling rats that scamper, bloodied, into the corners. The background is dark and the image appears nightmarish, stylised – like the inspiration for a Francis Bacon painting. It illustrates the pub sport of rat-catching, which became popular in the 1840s after bear-baiting and cock-fighting were banned. A special pit was dug in many pubs, and punters would place bets on how many rats a dog could kill in a certain amount of time. The image suggests the romanticised "savagery" of much folk art.

This darkness is undercut by the next gallery, which is filled with large, leering ship figureheads, painted in bright, carnivalesque colours. One of the most striking is a woman robed in blue, her hands behind her back, her breast exposed, her eyes glassy. She looks like a martyr, vividly sensuous and stunned at once. According to the Royal Navy Museum, figureheads were originally used as religious symbols to protect the ship. It was believed that the ship needed a pair of eyes in order to find its own way. Real women on board the ship were considered to be unlucky, but a female figurehead could calm a storm.

There are also four blatantly racist tobacconist shop signs. One is an early 20th-century figure of a "blackamoor" smoking a pipe. A blackamoor was a caricature of a black man that was used to sell goods imported during the slave trade and after. These figures show how ideas of the "exotic" and the "noble savage" were used as marketing devices, and how cultural stereotypes reinforced imperialist strategy. They are grotesque.

The final gallery conforms more closely to what people might expect of folk art. There are two bold red-and-white quilts, probably made by women, from the 1870s. They appear like abstract paintings; the one on the left was named The Drunkard's Path because of its meandering line of the red. They are attractive but not spectacular.

There is also a "clicker quilt" from the 1920s, named after the "clickers" who worked in the shoe factories in Norwich, where the quilt was made. It consists of irregular pieces of white linen outlined in red to create an elegant, abstract pattern. The linen pieces mimic the leather templates used in shoe manufacturing, which is a riddle because they are not the templates themselves.

While high art such as painting and sculpture was historically deemed "masculine", craft such as quilt-making was "feminine." This gendered division is challenged by the curators' inclusion of a Crimean War quilt from the second half of the 19th century, which was made by male soldiers in a state of what would now be called post-traumatic stress. The intensive embroidery work served as an outlet for their fractured nerves while they convalesced. Indeed, the quilt is stunning – geometric and flecked with terracotta colours.

McMillan suggests that horror vacui – the "compunction to fill up all empty pictorial space" – is the mark of the self-taught artist. This may be true for all artists, to some degree. But there is a subtext to this exhibition which needs to be teased out – how and why people without the resources or luck to become artists proper still felt the urge and found a way to express themselves. The subject of folk art would be better served by addressing class directly.

British Folk Art, Tate Britain, London SW1 (020 7887 8888) to 7 September