Kathmandu is the capital of Nepal and the principal city of the Kathmandu Valley, in Bagmati Province. Its name descends from Kasthamandap, the timber pavilion at Maru Tole beside the old Durbar Square; the Malla kings ruled the city as Kantipur, and its Newar inhabitants still call it Yen. Weaving belongs to the valley rather than to the capital's street plan. Looms and finishing sheds sit in Kathmandu itself, in the Tibetan quarter around Boudhanath on its north-eastern side, across the river in Lalitpur - old Patan - around Jawalakhel, and eastward towards Bhaktapur. A rug sold under the Kathmandu name comes from that cluster rather than from one quarter of the city.

Nepal had no knotted-pileThe surface of a rug or carpet, made of upright fibers in cut tufts or loops. In a hand-knotted rug it is formed by the cut ends of thousands of wool or silk knots tied onto the warp row by row, trimmed lightly during weaving and given its final height by shearing at finishing. Pile thickness, measured from the back of the rug to the top of the pile, typically runs from low, about 1/8 to 1/4 inch (3 to 6 mm), to high, about 1/2 to 5/8 inch (13 to 16 mm). Fine, dense designs are cut short to keep the pattern sharp; higher pile suits traffic and heavy furniture, lower pile suits door clearance and humid rooms.See in the carpet dictionary industry of any commercial size before the middle of the twentieth century. What exists today was built almost from nothing after 1959, when Tibetan families who had crossed the Himalaya were resettled in the valley and a handicraft center opened at Jawalakhel, with Swiss technical assistance, to give them work they already knew how to do. The craft was Tibetan rather than indigenous, and its market was foreign from the start, first visitors in Kathmandu and then importers abroad. Within a generation carpets had become one of the country's largest manufactured exports and the valley its main production center. This is a young tradition, and its youth explains a great deal about how the rugs look.

The weave itself is what most clearly separates these carpets from Persian ones. Rather than tying an individual knot on each pair of warps, the weaver runs a continuous length of yarn across the row, looping it around pairs of warps and around a metal gaugeIn machine-made carpets, refers to the distance between needles on the tufting machine. Lower gauge numbers indicate more needles per inch and a denser carpet.See in the carpet dictionary rod laid in front of them. When the row is complete the loops are cut along the rod and the rod is withdrawn, leaving a finished row of pile. This is the Tibetan or loop knot, and it gives a pile that feels dense, springy and slightly shaggy underfoot, with a softer and less exactly drawn line than a Persian knotThe asymmetrical knot of hand-knotted rugs, the counterpart of the symmetrical Turkish (Ghiordes) knot. The weaver wraps the yarn around one warp thread and passes it under the neighboring one, usually working by hand without a hook. On the back of the rug the knots look staggered or diagonal rather than like tidy squares, and the pile feels softer; the knot permits finer detail and higher knot density. In Iran, a rule of thumb ties it to the central, eastern, and southern rugs (Kashan, Isfahan, Nain, Kerman), while the northwest and west favor the Turkish knot, though exceptions exist. Fine curvilinear florals are often credited to it, but Turkish-knot rugs can be just as intricate.See in the carpet dictionary produces.

DensityA measure of how tightly a carpet is packed. In machine-made carpet it describes the fibers in the pile and is calculated by multiplying the face weight by 36 and dividing by the pile height; higher density generally indicates better durability and performance. In hand-knotted rugs it means knot density (KPSI, knots per square inch), counted on the back and averaged over several areas (150 KPSI is about 23 knots per cm²). Like image resolution, higher density allows finer curves and sharper designs, usually with a lower-trimmed pile and more labor, but it is not the sole measure of quality: bold geometric village rugs are made at low to medium density.See in the carpet dictionary is quoted differently here as well. Himalayan rugs are traditionally graded in knots per horizontal inch, as 60-knot, 80-knot or 100-knot quality, while Persian and most other hand-knottedA rug construction in which the weaver ties each knot of wool or silk pile yarn by hand around adjacent warp threads on a loom, then runs a weft through the row and beats it down. The cut knot ends form the pile, the warps and wefts form the foundation, and the warp ends become the fringe. A rug can take months or even years, and the work leaves subtle irregularities: patterns not perfectly symmetrical, opposite edges a few inches different in length, an uneven fringe. Authentic Persian, Oriental and Turkish rugs are hand-knotted, unlike hand-tufted rugs (sometimes sold as “handmade”) and machine-made ones, whose backs feel stiff and evenly aligned.See in the carpet dictionary rugs are measured in knots per square inchThe number of knots in one square inch of a hand-knotted rug (KPSI; 1 KPSI is about 15.5 knots per 10 x 10 cm), counted on the back with a ruler by multiplying the knots along one inch of height by those along one inch of width, averaged over two or three areas. More knots give sharper detail, like a higher-resolution screen, and, all else equal, somewhat more durability and a higher price, but density alone does not grade quality: Heriz and Bijar are durable at low to medium counts, while floral curvilinear designs blur without enough knots. Figures run from under about 80 for coarse tribal weaves such as Gabbeh and Qashqai, through roughly 120 to 225 for many village rugs and 300 to 700 for fine city rugs such as Nain and Isfahan, to 600 to 1,000 or more for pure silk Qum.See in the carpet dictionary, counted on the back across an inch each way and averaged over two or three parts of the pattern. The two figures are not interchangeable, and setting one against the other tells you very little. What matters more is whether the count suits the drawing: fine detail and curved lines need density or they blur, open grounds and geometry do not, and plenty of coarse rugs outlast fine ones.

WoolA natural animal fiber used for the pile, and in some rugs also the foundation, of high-quality rugs. It is durable, resilient, stain resistant and flame resistant, feels soft and cushioned underfoot, insulates against cold, and takes up dye readily and holds it for many years. It also traps dust particles, which helps reduce allergic reactions. Quality depends above all on where the sheep graze: high-elevation pastures and good feed give thicker, oilier wool, with Manchester, New Zealand and Ghazni wools the best-known prized examples. Early-spring shearing and hand spinning (finer, softer thread than machine spinning) improve it further, while thin, dry wool from dead sheep goes into cheaper rugs.See in the carpet dictionary comes from two sources and usually from both at once. Highland fleece from the Tibetan plateau is coarse, long in staple and high in lanolinThe natural wax that coats wool fibers and serves as the fleece’s own protection, waterproofing it. Wool from sheep raised at higher elevations is thicker and oilier ("fatty"), and a warm, slightly oily hand is a quick sign of real wool. In a carpet, the lanolin that remains repels liquids, so spills bead on the surface for a few moments instead of soaking in, one reason wool resists spills and soil. Hand spinning preserves it, while repeated harsh chemical cleaning strips it away, so gentle washing is recommended.See in the carpet dictionary, which makes it hard-wearing and lets it take dye with real depth; New Zealand woolWool sourced from New Zealand, ranked with Manchester and Ghazni wool among the three best-known high-quality wools for Persian and Oriental rugs; good rug wool of this kind feels thick and oily. Because it is imported rather than taken from local flocks, its use affects a rug's price. It is cited for the pile of Pakistan-woven Oushak, Ziegler and Peshawar rugs, sometimes paired with Ghazni wool, and for the thick pile of Kazak Azari rugs.See in the carpet dictionary is whiter, more even and spins more smoothly, and blending the two is standard practice rather than a compromise. CardingA wool-preparation step in which cleaned wool passes through a carding machine that lines the fibers up in one direction and removes any impurities still left. It follows scouring and carbonizing and comes before spinning, leaving the wool ready to be spun into yarn for the rug.See in the carpet dictionary and spinning are often still done by hand, which leaves the yarn slightly irregular, and that irregularity is part of why the finished surface catches light the way it does. Silk or bamboo viscoseA semi-synthetic fiber made from cellulose, used in carpets to create a silk-like appearance at a lower cost. Less durable than wool or synthetic fibers.See in the carpet dictionary is sometimes added in small quantities for highlights. The foundation is nearly always cotton, which holds its dimensions where a wool foundationA rug base in which the warp and weft threads are wool instead of cotton. It is typical of tribal rugs such as Baluchi, Turkoman and Gabbeh (Gabbeh and Quchan sometimes use goat hair instead), turns up in some Qashqai, Shiraz, small Bakhtiari and Iranian Azerbaijan pieces, and is common in older village and tribal rugs, including some Hamadan and very antique Karaja. Experts use it as a clue to age, since rugs made after about the 1930s usually have a cotton foundation, once machine-spun cotton became widely available. Wool's soft, less rigid structure gives the design a fluid, warm character, and the fringes are sometimes braided or in different colors. The drawback is that wool shrinks and stretches with humidity, so these rugs tend to be less straight than cotton-based ones.See in the carpet dictionary shrinks and pulls.

Color is where the valley parts company with the older Oriental repertoire most visibly. Vegetable dyes drawn from plants, seeds and flowers are used and give deep, harmonious grounds, but much of the output relies on modern dyes, because the greys, sands, charcoals and washed pastels the trade asks for were never part of a traditional dyer's range. AbrashSubtle shifts in color within a handmade rug, often visible as horizontal bands across the field. They arise because successive dye batches never match exactly, because differences in the wool's fat and oil content make colors change unevenly with age, and, in cream areas woven from undyed wool, because the fiber changes tone as it ages. Abrash often grows more distinct with age, so in an older rug it counts as a sign of natural dyes and hand production rather than a fault, while a newer rug is still checked for even color. Machine-made and some new hand-knotted rugs imitate it on purpose.See in the carpet dictionary, the gradual banding that appears where one dye lotA single batch of dye, together with the yarn colored with it, all of which takes the same shade. Natural dyes are made in small artisanal batches, and when one runs out the replacement cannot be matched exactly, so yarn from different lots differs slightly in tone. In a finished rug the difference shows as the color shifts known as abrash, which is read as a sign of hand dyeing, whereas a perfectly flat, uniform color suggests synthetic dyes and machine making.See in the carpet dictionary gives way to the next or where the wool took color unevenly, turns up here as readily as anywhere and is usually welcomed rather than corrected. Because a whole order tends to be dyed in one batch, color still runs more consistent than in village weaving, where yarn is bought and dyed piecemeal.

Patterns range from plain to almost architectural. Older Tibetan motifs survive - lotus flowers, cloud bands, dragons, and the small medallionA large motif at the center of a rug's field, around which the rest of the design is organized; the large central medallion is said to have been introduced in the Safavid era (16th-17th centuries). Floral medallions, typical of city rugs such as Tabriz, Kashan and Sarouk, are often read as a lotus blossom, and the motif has also been read as mirroring the interior dome of a mosque; geometric ones, often hexagonal or diamond-shaped, mark village and tribal rugs such as Heriz and Zanjan. A medallion may stand alone, come with four corner pieces, be flanked by smaller medallions above and below, or repeat down a runner. Rugs with no central motif are called allover. In a well-made rug the medallion sits at the center and the corners mirror one another, as closely as handwork allows.See in the carpet dictionary formats of the khaden sleeping rug - but the bulk of what the valley weaves is modern: abstract fields, stripes and grids, tone-on-tone textures, borderless grounds where the interest sits in the surface rather than in a drawn design. Cut-and-loop pileA carpet construction where the yarn forms loops that remain uncut on the surface. Available in level loop (all loops the same height) or multi-level loop (varying heights to create patterns or texture). Generally more durable and less prone to crushing than cut pile carpets.See in the carpet dictionary, in which some areas are left uncut, is one of the usual ways of getting that texture. Since the industry was built for export, it is unusually willing to weave to order, and custom sizes, shapes and colorways are ordinary requests rather than exceptional ones.

In use these are robust rugs. The looped knot packs a great deal of wool into the pile, so the carpet feels thick and resilient underfoot and copes well with a hallway or a family room, and the softer drawing means wear shows less than it would on a finely knotted floral field. Sizes run large, because the looms were set up for contract and export work, so genuinely big room-size pieces are easier to find here than in most weaving regions. The trade has also carried independent child-labor certification since the 1990s, when the first labeling schemes were set up for South Asian carpets, and labeled rugs are a normal part of it.

A Persian rug is a rug hand-knottedA rug construction in which the weaver ties each knot of wool or silk pile yarn by hand around adjacent warp threads on a loom, then runs a weft through the row and beats it down. The cut knot ends form the pile, the warps and wefts form the foundation, and the warp ends become the fringe. A rug can take months or even years, and the work leaves subtle irregularities: patterns not perfectly symmetrical, opposite edges a few inches different in length, an uneven fringe. Authentic Persian, Oriental and Turkish rugs are hand-knotted, unlike hand-tufted rugs (sometimes sold as “handmade”) and machine-made ones, whose backs feel stiff and evenly aligned.See in the carpet dictionary in Iran, and the tradition behind it is the oldest documented anywhere. The earliest surviving carpet, the Pazyryk rugThe oldest known pile carpet in the world, woven around the 5th century BC and discovered in 1949 in the frozen tomb of a Scythian noble in Siberia's Altai Mountains. Grave robbers left the burial mound open, so cold and moisture froze the chamber and sealed the carpet in ice for some 2,500 years. Its symmetrical knots, about 36 per square centimeter (roughly 230 per square inch), show that carpet weaving was already a mature art in antiquity. It is often described as the oldest Persian rug and as early evidence of tribal weaving, a craft that began as protection against cold and damp. It is displayed in the Hermitage Museum in St. Petersburg.See in the carpet dictionary, was found preserved in a frozen burial mound and dates to the fifth century BC — roughly 2,500 years ago — and it is already accomplished work, not a beginner's craft. What began as warm, hard-wearing floor coverings for tribal households grew, over those centuries, into the art form that every other rug-weaving country has borrowed from.

Two later chapters shaped what a Persian carpet looks like today. Under the Safavid dynastyThe Persian ruling house that reigned from 1501, beginning with Shah Ismail, into the 1730s, whose court patronage of painting, calligraphy and weaving made this the golden age of Persian rugs. Many museum and top-auction masterpieces come from the era, with Tabriz, Herat, Kashan and Kerman the largest centers. As patterns grew more complex, designers, often miniature painters, became separate from the weavers who worked from their drawings; the large central medallion, curvilinear and geometric layouts and richer flowers and vines became hallmarks, and patterns were standardized for export to Asian and European markets. The Afghan invasion of Isfahan in 1722 interrupted weaving in the main manufacturing centers for several years, though tribes and villages carried on.See in the carpet dictionary, from 1501 to 1732, the court promoted weaving alongside painting and calligraphy, and the workshops of Tabriz, HeratRugs from Herat, a historic city in western Afghanistan that was among the largest rug-producing centers of the Safavid period (16th to early 18th century), alongside Tabriz, Kashan and Kerman. The city also gives its name to the Herati design, a repeated diamond holding a small flower or leaves, with curved leaves at its sides, which is said to have originated there and is still woven in many Persian rugs.See in the carpet dictionary, Kashan and Kerman produced the masterpieces that now sit in museums. This is when the great central medallionA large motif at the center of a rug's field, around which the rest of the design is organized; the large central medallion is said to have been introduced in the Safavid era (16th-17th centuries). Floral medallions, typical of city rugs such as Tabriz, Kashan and Sarouk, are often read as a lotus blossom, and the motif has also been read as mirroring the interior dome of a mosque; geometric ones, often hexagonal or diamond-shaped, mark village and tribal rugs such as Heriz and Zanjan. A medallion may stand alone, come with four corner pieces, be flanked by smaller medallions above and below, or repeat down a runner. Rugs with no central motif are called allover. In a well-made rug the medallion sits at the center and the corners mirror one another, as closely as handwork allows.See in the carpet dictionary appeared, and when designs grew elaborate enough that a separate designer — often a miniature painter — drew the pattern onto a cartoon for the weaver to follow. The second chapter came in the nineteenth century, under the Qajar dynastyThe era of the Qajar dynasty, which ruled Persia in the 19th century and produced the largest rug output in Persian history. Weaving revived after the turbulence of the 1700s that had halted the main manufacturing centers, and exports to Europe and America thrived, with England and Germany the biggest buyers. Newer centers such as Sultanabad and Kashan rose alongside Tabriz and Kerman, and European and American companies set up their own manufacturing hubs in Persia. Rugs from these large factories follow standardized, easily recognized designs, unlike village and tribal rugs, whose weavers still design their own patterns.See in the carpet dictionary, when production reached its historical peak, exports to Europe and America boomed, and the workshop industry whose descendants still weave today took its modern shape.

The trade sorts Persian rugs into three families. City rugs — Tabriz, Kashan, Kerman, Nain, Isfahan — are woven in workshops from a drawn design, carry the highest knot densities and come in the widest range of colors, sizes and patterns. Village rugs such as HerizBold village rugs from the Heriz area of northwestern Iran, near Tabriz, and the best-known of all Persian village rugs. A coarse, tough wool pile on a cotton foundation, usually double-wefted for extra thickness, and a low-to-medium knot density (commonly quoted at about 120 to 170 KPSI, roughly 1,900 to 2,600 per 10 by 10 cm) make them very durable; the wool's strength is traditionally credited to copper-bearing mountain water. The classic design is a large angular medallion with four corner pieces, sometimes an allover layout, in a rust red traditionally credited to copper minerals in the local river, with dark navy and cream. Bakshaish and Serapi, the latter now over a century old, are their older forms.See in the carpet dictionary, BakhtiariColorful rugs of the Bakhtiari, a Zagros Mountains tribe that was nomadic until much of it settled southwest of Isfahan in the 19th century and whose weaving now spreads across more than 200 villages; smaller pieces tend to be tribal work and larger ones come from the region's villages. The foundation is usually cotton under a wool pile from the tribe's own sheep, though some small tribal pieces are wool throughout, and every row is beaten down so hard that the pile ends up dense and long-lasting. The signature layouts are the garden panel design (Khesti, also spelled Kheshti), a grid of framed squares that each show a garden scene meant as a view of paradise, and the medallion-and-corner design with a semi-geometric center medallion. Deep red and dark navy are the usual field colors.See in the carpet dictionary and KarajaVillage rugs from a group of villages in the Azerbaijan region of Iran, at the western edge of the Heriz weaving area and named for the village of Karaja at their center. Wool pile on a cotton foundation (very old pieces may have a wool one), Turkish knot and single weft, so the pile is thinner and softer than the usually double-wefted Heriz, and knot density is low to medium. Two bold geometric medallions with hook-like edges typically alternate down a runner, often on a different ground color with each repeat, and on wide rugs the repeated medallions read as a geometric allover, in orange-reds, blues, creams and browns. Their soft, thin pile and great lengths, some over 20 feet (6 m), make them popular as hallway and stair runners.See in the carpet dictionary sit in between, mostly geometric and largely woven from memory. Tribal rugs — Baluch, TurkomanTribal rugs woven by Turkoman (Turkmen) nomads, whose forebears came from the Afghan and Uzbek region and who later settled in the Turkmen region of Iran. Rows of octagonal guls (“flowers”) cover a deep red, reddish-brown or occasionally cream field, accented in black, blue, green or beige; prayer designs also occur. Foundation and pile are usually wool, said to come from the soft undercoat of Karakul sheep, though a cotton foundation is occasionally used. In older pieces each tribe kept its own gul design, whereas newer rugs freely mix them. Turkoman designs inspired Bokhara and Khal Mohammadi rugs and are the Persian design closest to Baluchi work, which they predate; the low-to-medium pile suits places where doors swing over the rug.See in the carpet dictionary, QashqaiTribal rugs woven by the Qashqai, a nomadic tribe of southwestern Iran that unites Turkic, Arab, Kurdish and Lur groups and has lived in the region since at least the 16th century. Designs come from memory rather than written plans, pairing geometric and medallion layouts, occasionally in a simpler, sparsely detailed form, with animals, plants and household objects, in jewel-tone reds, saffron gold and indigo, often on deep red or dark navy grounds. The thick, hard-weaving wool of the tribe's own flocks is durable yet soft, forming a medium-height, dense pile on a cotton or wool foundation that suits busy areas; compact looms keep sizes small, typically 4 x 6 ft (1.2 x 1.8 m) or 5 x 7 ft (1.5 x 2.1 m) plus runners.See in the carpet dictionary, each named after the people who weave it — are made on small portable looms, so they run smaller, and their bold geometric drawing comes from the weaver's own head rather than from paper.

The design vocabulary draws on a deep stock of motifs: Shah AbbasiA classic Persian floral style named after the Safavid ruler Shah Abbas, which began as a royal court pattern about 400 years ago. Its main features are stylized, feather-like palmette leaves and lotus flowers, the lotus being an ancient symbol of long life, arranged in strict symmetry with scrolling ornament around a central medallion, often a rosette. Early examples favored deep reds and blues, while later rugs in this style often turn to muted neutral tones. The design appears in Kashan, Nain and Tabriz rugs.See in the carpet dictionary palmettes, flowing arabesques, the small repeating Herati patternA classic Persian design built on a diamond repeated across the field, with a small flower or leaves inside each diamond and curved leaves at its sides; the leaves are read as stylized fish, said to circle a lotus. The name comes from Herat, the city in Afghanistan where the design is said to originate; it is also called the fish design, and Mahi means “fish” in Persian. It is one of the three main design families, woven as an allover pattern or around a central medallion with diamonds inside and outside it, and it sometimes appears as a thin border. It is common in Tabriz, Sarouk, Mashhad, Moud, Bijar, Hamadan, Abadeh, Zanjan, Kerman and Kashan rugs.See in the carpet dictionary, medallions, garden and tree-of-life compositions. These combine with regional habits into styles a practiced eye can place at a glance, from the bold geometric medallions of Heriz to the fine curvilinear florals of Isfahan.

The classic palette is built on natural dyes: madderThe root of the madder plant (Rubia tinctorum), a natural red dye and the source of the terracotta tones in Persian and Oriental rugs. Together with indigo and walnut husks it is among the plant dyes used to color the wool, bonding to its natural lanolin. Slight shade variations within one color area, known as abrash, are normal in rugs dyed this way.See in the carpet dictionary reds, indigo blues, saffron yellows and soft ivory tones, settled into combinations refined over centuries. Natural dyes age gracefully, mellowing into the patina that older rugs are prized for, and slight shifts of tone between dye batchesA single batch of dye, together with the yarn colored with it, all of which takes the same shade. Natural dyes are made in small artisanal batches, and when one runs out the replacement cannot be matched exactly, so yarn from different lots differs slightly in tone. In a finished rug the difference shows as the color shifts known as abrash, which is read as a sign of hand dyeing, whereas a perfectly flat, uniform color suggests synthetic dyes and machine making.See in the carpet dictionary — the effect called abrashSubtle shifts in color within a handmade rug, often visible as horizontal bands across the field. They arise because successive dye batches never match exactly, because differences in the wool's fat and oil content make colors change unevenly with age, and, in cream areas woven from undyed wool, because the fiber changes tone as it ages. Abrash often grows more distinct with age, so in an older rug it counts as a sign of natural dyes and hand production rather than a fault, while a newer rug is still checked for even color. Machine-made and some new hand-knotted rugs imitate it on purpose.See in the carpet dictionary — are a mark of small-batch natural dyeing, not a flaw.

The pileThe surface of a rug or carpet, made of upright fibers in cut tufts or loops. In a hand-knotted rug it is formed by the cut ends of thousands of wool or silk knots tied onto the warp row by row, trimmed lightly during weaving and given its final height by shearing at finishing. Pile thickness, measured from the back of the rug to the top of the pile, typically runs from low, about 1/8 to 1/4 inch (3 to 6 mm), to high, about 1/2 to 5/8 inch (13 to 16 mm). Fine, dense designs are cut short to keep the pattern sharp; higher pile suits traffic and heavy furniture, lower pile suits door clearance and humid rooms.See in the carpet dictionary is almost always woolA natural animal fiber used for the pile, and in some rugs also the foundation, of high-quality rugs. It is durable, resilient, stain resistant and flame resistant, feels soft and cushioned underfoot, insulates against cold, and takes up dye readily and holds it for many years. It also traps dust particles, which helps reduce allergic reactions. Quality depends above all on where the sheep graze: high-elevation pastures and good feed give thicker, oilier wool, with Manchester, New Zealand and Ghazni wools the best-known prized examples. Early-spring shearing and hand spinning (finer, softer thread than machine spinning) improve it further, while thin, dry wool from dead sheep goes into cheaper rugs.See in the carpet dictionary, and the wool decides much of the rug's quality. The best fleece comes from high-altitude flocks, where it grows thicker and richer in natural oils; spring-sheared wool beats the autumn clip, and hand-spun yarnWool yarn spun from cleaned, carded fleece by hand or on a manual wheel rather than by machine, after which the spun threads are twisted together into thicker, stronger strands before dyeing. It gives finer, softer threads than machine spinning, so the wool feels softer and looks shinier, and hand spinning is said to preserve the wool's natural lanolin. It is usual in Kazak and Peshawar rugs woven in Pakistan and in Afghan Khal Mohammadi rugs, all of which are also colored with natural dyes.See in the carpet dictionary gives a finer, softer thread than machine spinning. Fine pieces add silk highlights to a wool pile, and the finest are woven in pure silk. Foundations are usually cotton in city weaving, wool in tribal and older pieces, silk at the very top of the range.

Every knot is tied by hand, one at a time, in one of two forms: the asymmetric Persian knotThe asymmetrical knot of hand-knotted rugs, the counterpart of the symmetrical Turkish (Ghiordes) knot. The weaver wraps the yarn around one warp thread and passes it under the neighboring one, usually working by hand without a hook. On the back of the rug the knots look staggered or diagonal rather than like tidy squares, and the pile feels softer; the knot permits finer detail and higher knot density. In Iran, a rule of thumb ties it to the central, eastern, and southern rugs (Kashan, Isfahan, Nain, Kerman), while the northwest and west favor the Turkish knot, though exceptions exist. Fine curvilinear florals are often credited to it, but Turkish-knot rugs can be just as intricate.See in the carpet dictionary, usual in central and eastern Iran, or the symmetric Turkish knotOne of the two main knots of hand-knotted rugs, also called the symmetrical knot (the other being the asymmetrical Persian or Senneh knot). The yarn is looped around two adjacent warp threads with both ends emerging between them, so the back shows small, even, squarish knot heads; weavers often tie it with a hook. Named after the town of Ghiordes (modern Gördes) in Turkey, it is typical of Turkey, the Caucasus and northwestern Iran (Tabriz, Bijar, Heriz, village Hamadan), where Seljuk Turks are said to have introduced it, and gives a durable, precise pile. The Persian knot is often credited with finer detail, yet knot type is a tendency, not a limit: Tabriz rugs woven with the Turkish knot reach about 500 knots per square inch (roughly 78 per cm²).See in the carpet dictionary, common in the north-west ever since Seljuk weavers introduced it in the eleventh and twelfth centuries. A large carpet holds in the region of two million knots and can occupy a weaver for about a year.

Knot densityThe number of knots in one square inch of a hand-knotted rug (KPSI; 1 KPSI is about 15.5 knots per 10 x 10 cm), counted on the back with a ruler by multiplying the knots along one inch of height by those along one inch of width, averaged over two or three areas. More knots give sharper detail, like a higher-resolution screen, and, all else equal, somewhat more durability and a higher price, but density alone does not grade quality: Heriz and Bijar are durable at low to medium counts, while floral curvilinear designs blur without enough knots. Figures run from under about 80 for coarse tribal weaves such as Gabbeh and Qashqai, through roughly 120 to 225 for many village rugs and 300 to 700 for fine city rugs such as Nain and Isfahan, to 600 to 1,000 or more for pure silk Qum.See in the carpet dictionary is the figure newcomers fixate on, and the finest silk-foundation pieces do reach as much as 1,000 knots per square inch. But densityA measure of how tightly a carpet is packed. In machine-made carpet it describes the fibers in the pile and is calculated by multiplying the face weight by 36 and dividing by the pile height; higher density generally indicates better durability and performance. In hand-knotted rugs it means knot density (KPSI, knots per square inch), counted on the back and averaged over several areas (150 KPSI is about 23 knots per cm²). Like image resolution, higher density allows finer curves and sharper designs, usually with a lower-trimmed pile and more labor, but it is not the sole measure of quality: bold geometric village rugs are made at low to medium density.See in the carpet dictionary only matters as far as the drawing demands it: a curvilinear Isfahan needs a fine weave to stay sharp, while a geometric Heriz is famously durable at a modest count. Material, symmetry, color harmony and condition say more about quality than any single number.

Persian carpets settle into modern rooms as naturally as classical ones, as a focal point in a living room, a foundation under a dining table or a quieter accent in a bedroom. Care is undemanding: gentle vacuuming without a rotating brush, an occasional turn for even wear, and a professional wash about every five years — sooner in a hallway or entrance, less often in a quiet room.

A hand-knotted Persian rug tends to outlast its owners. Pieces a century old regularly survive in fine condition, their colors settled and their pile supple, often looking better than when they left the loomThe frame on which the warp (vertical) threads are strung first and held under tension so the weft (horizontal) threads can be interlaced through them and the knots tied onto them. Hand-knotted rugs are made on simple looms, from those set up in weavers' homes to the compact, transportable ones of nomadic weavers, where every knot is tied by hand. Loom size sets rug size: nomads' small looms typically yield rugs no larger than about 4 x 6 or 5 x 7 ft (1.2 x 1.8 m or 1.5 x 2.1 m), city workshops with very large looms weave palace sizes, and the number of looms a workshop runs gauges its scale. Wooden looms in tribal and village weaving expand and contract over time, one cause of crooked rugs. Power looms such as Wilton, Axminster, and Jacquard, the industrial descendants, make machine-woven carpet.See in the carpet dictionary. A well-chosen, well-kept rug holds its worth and passes down as a family heirloom rather than being replaced — which is precisely what the knots, the wool and the dyes were always for.