How Is a Tapestry Made? Pictures Built Thread by Thread

All woven cloth consists of warp threads held taut on a loom and weft threads passed across them. In ordinary weaving the weft runs the full width and the colour pattern comes from the sequence of threads. In tapestry weaving the weft is discontinuous: each colour is carried on its own small bobbin and worked back and forth only across the region where that colour appears, then turned and worked back. The weft is packed down tightly so that it covers the warp completely, which is why a tapestry shows no warp on the surface and why the design reads identically as a picture rather than as a pattern of interlacing. The warp therefore contributes strength and nothing visual, and the fineness of a tapestry is measured in warp threads per centimetre, with coarse work at around five and the finest at more than twenty, which determines how much detail is achievable.

The process separates the designer from the weaver completely, which is why tapestries are catalogued under two names:

• •A painter produces a small design, and it is then enlarged to full size as a cartoon, a painted or drawn guide the exact dimensions of the finished piece; Raphael's cartoons for the Sistine Chapel tapestries survive and are treated as major paintings in their own right
• •The cartoon is placed beneath or behind the warp so the weaver follows it directly, and on a high-warp loom it is traced onto the warp threads themselves
• •Weaving usually proceeds sideways, with the design turned ninety degrees, because vertical slits between colour areas weave more easily than horizontal ones
• •On a high-warp loom the warp is vertical and the weaver works from the back, checking the front with a mirror; on a low-warp loom it is horizontal and treadles speed the work
• •The weaver interprets the cartoon rather than copying it, choosing how to blend colours, which is why the same cartoon woven twice gives noticeably different results
• •Because weaving from the back reverses the image, published designs and finished tapestries are frequently mirror images of each other

Discontinuous weft creates a structural weakness at every boundary between two colours. Where the boundary runs along the warp direction, the two colour areas turn back on adjacent warp threads and never interlock, leaving a vertical slit. Weavers solve this in several ways: sewing the slits closed afterwards, which is the common European practice; interlocking the two wefts around a shared warp thread; or dovetailing them so they alternate around one thread. Curved and diagonal boundaries avoid long slits naturally, which is one reason tapestry design favours flowing outlines. Shading presents a second problem, since there is no way to mix paint, so gradations are produced by hatching, interleaving fine tapered strips of two colours so they optically blend, a technique developed to an extraordinary level in Flemish work. Metal thread, gold or silver wrapped around a silk core, was woven in for highlights, and a great deal of it has since been picked out and melted, damaging many surviving pieces.

In the fourteenth to sixteenth centuries a major tapestry set cost more than a painting by any master and frequently more than a building, because it consumed enormous quantities of wool and silk and years of skilled labour. That expense made it a statement of wealth, and its portability made it a practical one: a ruler travelling between residences carried the tapestries, hanging them to transform a bare stone hall, insulate it and announce whose hall it was. Sets told stories across multiple panels, drawn from scripture, classical myth, chivalric romance and dynastic history, and functioned as visible political argument about legitimacy and lineage. The great production centres were in Flanders, above all Arras, whose name became a word for the hangings themselves and is what Polonius hides behind in Hamlet, along with Tournai and Brussels, and later the royal Gobelins manufactory in Paris and Mortlake in England. Demand collapsed in the eighteenth century as fashion turned to painted decoration and wallpaper.

Tapestries are among the most fragile large objects in museum collections because they are heavy textiles hung by their own weight. Gravity pulls continuously on the upper edge, distorting the weave and eventually tearing it, so conservation practice now includes supporting the full weight across a lining and rotating pieces off display. Light causes irreversible fading, and because dyes fade at different rates the colour balance shifts as well as dimming, which is why the reverse of an old tapestry frequently shows brilliant colours the front lost centuries ago and why display lighting is kept very low. Wool and silk are food for moths and carpet beetles, so pest management is constant. Many pieces have been cut down to fit walls, had their metal thread removed, or been crudely repaired with mismatched wool. Conservation is correspondingly slow and expensive, with major projects on single hangings running for years, and the accepted approach now favours stabilising what survives over restoring the appearance.

The most famous so-called tapestry in the world is not one. The Bayeux Tapestry, which tells the story of the Norman conquest of 1066 across about seventy metres of cloth, is embroidery: coloured woollen yarns stitched onto a plain woven linen background, which remains visible between the figures. It was probably made in England, perhaps at Canterbury, within a couple of decades of the battle, by skilled needleworkers following a planned design, and it survives in Normandy. Technically it is the opposite of everything described above, since the picture was added to finished cloth rather than built into the cloth as it was woven.

The word has spread in other directions too. The needlework kits sold as tapestry are canvas embroidery, in which stitches of wool are worked through a stiff open-mesh canvas, and the result can look like woven tapestry from a distance while being built entirely differently. Machine-made furnishing fabrics marketed as tapestry, woven on Jacquard looms since the nineteenth century, use continuous wefts with the pattern produced by lifting different warp threads, so the colours float across the back in long runs. Turning a piece over is the quickest test: a true tapestry shows loose thread ends and small joins wherever each colour starts and stops.

By the early twentieth century tapestry had become a costly way of copying oil paintings, with workshops dyeing thousands of shades to imitate brushwork. The French artist Jean Lurçat set out to reverse that. After seeing the medieval Apocalypse Tapestry at Angers in the late 1930s, he worked with the old weaving town of Aubusson to return to the medium's own strengths: bold flat areas of colour, strong outlines and coarser, quicker weaving. His cartoons were drawn in outline, with each area marked by a number matching one of a limited palette of dyed wools, so the weaver followed numbers rather than painted shading.

The approach drew major artists back to the loom, and some of the largest tapestries ever woven date from those decades. Graham Sutherland's Christ in Glory, which fills the wall behind the altar of the rebuilt Coventry Cathedral, was woven at Felletin, near Aubusson, and hung in time for the cathedral's consecration in 1962; it is more than twenty metres tall and was woven as a single piece. Aubusson tapestry was added to UNESCO's list of intangible cultural heritage in 2009, and its workshops still weave designs by living artists, using methods that a medieval weaver would recognise.

Among the most admired tapestries in the world are the six panels of The Lady and the Unicorn, woven around 1500, probably in the southern Netherlands for a French noble family, and now in the Musee de Cluny in Paris. Each shows a lady with a lion and a unicorn on a red background scattered with flowers and small animals, a style known as millefleurs, a thousand flowers.

Five of the panels are usually read as representing the five senses: touch, taste, smell, hearing and sight. The sixth, inscribed with the words my sole desire, has puzzled scholars for generations, with interpretations ranging from love to the renunciation of the senses. The tapestries were rediscovered in a French chateau in the nineteenth century and championed by the writer George Sand.

In a tapestry the picture is woven rather than applied, using weft threads that travel only across their own patch of colour and are packed down to hide the warp completely. A painter supplies a full-size cartoon and a weaver interprets it, usually working sideways and from the back, so finished pieces are frequently mirror images of the design. Slits form wherever two colours meet along the warp and must be sewn or interlocked. The cost of wool, silk and years of labour made tapestries the most expensive furnishings in Europe.