The Rug Library

For fragile rugs, conservators vacuum through a protective screen, adjusting suction so dirt lifts out without the textile itself being drawn up.

Upright vacuum cleaners and power heads with beater bars are considered inappropriate for cleaning museum textiles, and HEPA-filtered vacuums at reduced suction are preferred.

Rotating a rug from time to time helps it wear more evenly, and the underlay and rug should be checked routinely for signs of damage.

The Carpet and Rug Institute advises blotting spills with a clean white cloth or paper towel and working cleaning solution from the edge of a spot towards the centre, rather than scrubbing.

Scrubbing or brushing a spill can fray fibres and change the texture of carpet pile, which is why rug-care guidance stresses blotting instead.

Potted plants, especially clay pots that transmit moisture, are a common cause of hidden damp, mildew and rot in the rug beneath them.

The Carpet and Rug Institute advises scooping up semi-solid spills with a spoon, vacuuming up dried solid bits, and acting quickly on any spill.

A knotted-pile carpet has a raised surface made from the cut ends of knots tied onto the warps, with rows of knots held in place by weft passes.

Kashmiri hand-knotted carpets are made as silk-on-silk, silk-on-cotton, all-wool, and 'staple' qualities using synthetic silk or mercerised cotton.

A gabba is a Kashmiri floor rug made by piecing together old woollen blankets or cloth, which are milled, dyed and then covered with chain-stitch or appliqué embroidery.

The Kashmiri namda is a felted rather than woven rug: layers of washed wool are wetted, pressed and rolled until the fibres mat together, then usually embroidered.

Indian pile carpets are generally knotted in wool on a cotton warp and weft, with silk foundations used more rarely, for example in Kashmir.

Warps are the threads running the length of a rug and form its foundation; their ends are often left free to become the fringe.

Wefts are the yarns passed across a rug's width, over and under the warps, locking rows of knots in place in pile rugs or forming the whole design in flat-weaves.

A kilim has no pile: warp and weft are simply interlaced into a flat weave, with no extra yarn knotted in.

Kashmiri rugs are hand-knotted mainly in pure wool or pure silk, and occasionally in wool-and-silk blends.

In gabba making, old woollen cloth is milled by carding and washing it in warm soapy water so that it shrinks into a dense, soft base before embroidery.

The Met's Mughal carpet with irises and tulips, from Kashmir or Lahore about 1650, measures about 432 × 208 cm (roughly 14 × 7 ft), a long, narrow format.

The Met's lattice-and-blossom fragments make up about a quarter of a Mughal carpet once over 23 feet long, which the museum calls enormous for a carpet of such fine quality.

A Met millefleur carpet from Kashmir measures about 3.9 × 3.8 metres, an almost square format.

The Girdlers' Carpet, woven in Lahore and in London by 1634, measures about 27 × 8 feet, a long, narrow shape suited to its use as a table covering.

Anatolian prayer rugs were made small enough for one person; a Milas example at the Met measures about 165 × 112 cm.

A Mughal single-plant 'prayer rug' in the Thyssen-Bornemisza collection measures about 125 × 90 cm, showing how small some finely knotted court pieces were.

Because of its monumental size, over 4 × 5 metres, and restrictions set by its collector, the Wagner Garden Carpet has rarely been displayed, only three times in about 20 years before its North American tour.