Kilim or pile rug: how the two are made, and where each belongs

A kilim is woven flat. Coloured weft threads are packed down so tightly that they hide the warp completely, and the surface is the weave itself, with no pile. A pile rug is knotted. Short lengths of wool are tied around the warp threads, row after row, and cut, so that a field of tufts stands up from the foundation.

In a house the difference is simple. A kilim is thin, light and graphic, and slides under a door. A pile rug is thick, soft and warm, and is where you sit on the floor. The pile is also what takes the wear, which is why a kilim of the same wool wears through sooner.

The word kilim comes from the Persian gilim, a mat or a blanket, and the technique is old. The explorer Aurel Stein found flat-woven fragments at Hotan, in western China, from at least the fourth or fifth century. The oldest knotted pile carpet anyone has found is older still: pieces from Yanghai, also in China, dated to about 700 BCE, and the famous Pazyryk carpet from a frozen tomb in the Altai a few centuries later.

On a flatweave loom, the weaver passes the weft over and under the warp and beats it down hard. Where two colours meet, she turns each thread back on itself. That leaves a small vertical slit between the colours, which is why kilims have such clean, stepped edges and why their geometry looks sharp. Some weavers interlock the two threads instead to close the slit; the line softens a little. The warp only shows at the ends, as fringe. Because the pattern is made by the weft itself, a kilim often shows the same design on both sides.

On a pile loom, the weaver builds a foundation the same way, but between rows of weft she ties a row of knots. Each knot wraps a pair of warp threads, and its two ends rise to the front. When the row is done she beats it down, passes more weft, and starts again. The tufts are trimmed to height. A Middle Atlas rug can carry a pile of a centimetre or of three; the deeper the pile, the heavier the rug. A Beni Ourain of three metres by two, with a deep pile, can weigh fifteen kilos or more. A kilim of the same size can be folded over an arm.

Moroccan weavers often mixed the two. Some Middle Atlas pile rugs have bands of flatweave across them, or a flat-woven strip at the ends. The rag rugs of the south-east, studied by the anthropologist Cynthia Becker, were made the same way: a few rows of flat weaving, a row of knots tied with strips of cloth, and back to flat weaving. A loom does whatever the household needs it to do.

So the choice in a house is about use, not rank. Pile belongs where people are barefoot, sit on the floor or want quiet: a bedroom, a salon, a cold tiled room in winter. It hides a lot and forgives a lot. Flatweave belongs where things move: a corridor, under a dining table where chairs slide in and out, in front of a door that must still open, or on a wall. A pattern with a strong direction needs enough floor showing to read.

Two cautions. A flat rug on a smooth floor will travel, so it wants a pad underneath; which pad depends on the floor, and a wrong one can mark it. And flat is not the same as easy. A kilim has no pile to hide dirt, but its slits, edges and dyes need the same care as any wool rug.

Turn either one over and the method is there to read: on a kilim, the same pattern again; on a pile rug, the rows of knots, a little uneven, one by one.