Persia, a Museum of Materials · Hall 11 · Wool

A picture made of knots

Look closely at a carpet and the flowers dissolve into dots: every dot is one knot of dyed wool, tied by hand round two threads and cut short. Finer knots make a sharper picture, and cost more days. The Ardabil carpet of 1539 has about 26 million of them. Here is a small rug, 60 by 90 cm, drawn by code: move the loupe over it, change the fineness of the knots, and weave it.

86,400 knots14 days at 6,000 knots a day

Knots per 10 cm

1,600

knots per dm² · 28 raj

Weave it

86,400 knots

14 days at 6,000 knots a day

Knots per 10 cm40

Choose the dyes

Field

Medallion

Border

Flowers

Madder redmadder root
Indigoindigo leaves
Ivoryundyed wool
Weld yellowweld, onion skins
Walnut brownwalnut husks, oak

Material: Wool pile on cotton or silk warps
Oldest: The Pazyryk carpet, about 2,400 years old
Finest classic: The Ardabil carpet, 1539–40, some 26 million knots
Dyes: Madder, indigo, weld, walnut
Living craft: UNESCO intangible heritage, Fars and Kashan, 2010

Try this

Drag the loupe to the edge of the medallion. Every step of the curve is one knot: a carpet cannot draw a line finer than a knot.
Pull the knots down to 15 per 10 cm. The picture goes coarse, like a photo with too few pixels. Push them up to 70 and it sharpens, but the count runs to hundreds of thousands.
Press Weave it. The rug grows from the bottom, row by row, the way it does on a loom, and the counter shows how many days it would take.

The rug is drawn by code in the layout Safavid weavers used, a medallion with corner pieces and a border; it copies no real carpet. Knot counts are real arithmetic for a 60 × 90 cm rug. The days are counted at 6,000 knots a day, about one every five seconds for eight hours; a fast weaver ties more, a fine silk rug takes longer. The five dyes are the classic ones, though real dyers had many more.

Two ways to tie a knot

Each knot is a short length of yarn looped round two warp threads and cut, so that its two ends stand up as pile. The asymmetric knot, often called Persian, wraps one warp and passes under the other; the symmetric knot, often called Turkish, wraps both and brings its ends up between them. Rows of knots alternate with rows of weft, beaten down with a comb.

Asymmetric (Persian)

Symmetric (Turkish)

The Pazyryk carpet

The oldest pile carpet we have was found in 1949 by the archaeologist Sergei Rudenko, frozen in a chief’s tomb in the Altai mountains of Siberia. It is about 2,400 years old, 183 by 200 cm, and fine: about 36 knots to the square centimetre. Round its borders walk a procession of deer and a line of horsemen. Whether it was woven in Persia or Armenia is still argued; it is kept in the Hermitage in St Petersburg.

Twenty-six million knots

The Ardabil carpet was finished in 1539–40, in the reign of Shah Tahmasp, and signed by “a servant of the court, Maqsud of Kashan”. It is more than ten metres long, wool on a silk foundation, with 300 to 350 knots to the square inch: about 26 million in all. Its medallion is a sixteen-pointed star; the pattern inside the dome of the Sheikh Lotfollah Mosque, built eighty years later, resembles it. It is in the Victoria and Albert Museum in London; its twin is in Los Angeles.

From root to red

The colours came from plants and were fixed with mordants: red from madder root, blue from indigo leaves, yellow from weld and onion skins, brown from walnut husks and oak. A design was drawn on squared paper, one square to a knot, and read aloud to the weavers. In 2010 UNESCO listed the traditional skills of carpet weaving in Fars and in Kashan as intangible heritage of humanity.

Episode 11 of 12

Still alive today

In Fars, UNESCO recorded in 2010, weaving is passed on orally and by example, mothers teaching daughters; and in Iran’s bazaars a carpet’s fineness is still quoted in raj, the knots in 7 cm or so of its width.

Questions people ask

What does “raj” mean?

The number of knots in one gereh, a length of about 7 cm. A 40-raj carpet has 40 knots in every 7 cm of its width, about 57 to the 10 cm, or 3,300 to the square decimetre.

How fine can a carpet be?

Hand-made rugs run from about 16 to 800 knots per square inch, that is 2.5 to 125 per square centimetre. The Pazyryk carpet has 36, the Ardabil 47 to 54. The finest silk rugs go far beyond.

How long does a carpet take?

It depends on the size and the fineness. At a few thousand knots a day, a small rug like the one here takes weeks; a large fine carpet takes a workshop years.

Why compare knots with pixels?

Because they are the same idea: a picture built from dots of colour on a grid, where the fineness of the grid sets how much detail the picture can hold. Lab 001, Pixel & Sound, shows how a screen does it; a carpet did it first.

Where can I see these carpets?

The Pazyryk carpet is in the State Hermitage Museum in St Petersburg; the Ardabil carpet in the Victoria and Albert Museum in London, and its companion in the Los Angeles County Museum of Art.

Continue your visit

Before the finale, a special…

Winter comes: the longest night of the year, a quilt over a warm korsi, and a book of poems opened at random to answer a silent wish.
Yalda special · The longest night →

NextYalda special · The longest nightOpen the special →EarlierHall 10 · Glazed Tile · Build a girihEnter the hall →The museumThe entrance · all twelve halls, oldest firstBack to the entrance →

Sources: Wikipedia, “Pazyryk carpet”, “Ardabil Carpet”, “Persian carpet” and “Knot density”; UNESCO Intangible Cultural Heritage lists, “Traditional skills of carpet weaving in Fars” and “in Kashan” (2010).

The rug and the knots are drawn with code by Bridge Labs.