Mahallat is a city and county seat in the south-eastern corner of Markazi Province, Iran, about 100 kilometres by road from the provincial capital ArakSee in the carpet dictionary. Khomein and Delijan are its neighbours inside the province, the border with Isfahan Province runs just to the south, and the roads out of it lead north towards QomSee in the carpet dictionary and south towards Isfahan. The name is a plural, built from the Persian and Arabic word for a quarter or a neighbourhood, so it means something close to the quarters: a town grown together out of several separate settlements. Locally the place is better known for its hot springs, its travertine quarries and its flower nurseries than for looms, and its carpets belong less to the town itself than to the commercial weaving district around it.

That district is centred on Arak, a city that carried the name SultanabadSee in the carpet dictionary until it was renamed in the twentieth century, and in the late nineteenth and early twentieth centuries its carpets were prized across Europe and America. Weaving there was never a single product. Each satellite village carried its own name and its own grade, from workshop weaves such as SaroukSee in the carpet dictionary, some fifty kilometres north of Arak, down to the coarser village carpets of the surrounding countryside. Mahallat sits at the village end of that ladder, and in the trade you will almost always meet the weave under the shortened grade name Mahal, which survives as well in the label Ziegler MahalSee in the carpet dictionary, used for the district's carpets woven to European order.

Layout is the first thing to read on one of these carpets. Where a city rug is usually built around a central medallionSee in the carpet dictionary, the village carpets of this district characteristically fill the whole field instead: repeating palmettes, floral sprays, angular vine scrolls and small rosettes spread edge to edge in a lattice descended from the Harati pattern. Each motif is drawn a little differently from its neighbours, freehand rather than traced from a cartoon, so the repeat breathes instead of marching. A terracotta or rust-red border of rosettes and vine swirls typically frames the whole thing.

Drawing at this end of the district is rustic rather than refined, and that is the character of the weave rather than a shortfall in it. Unlike the precise curvilinear floral of the city workshops, these vines turn in angles, the symmetry reads as strong and almost tribal, and the palmettes are often oversized, closer to architecture than to botanical illustration. The Shah AbbasiSee in the carpet dictionary palmetteSee in the carpet dictionary and the stylised lotus, Safavid court motifs in origin, come off these looms reworked with village grace. Anyone hoping for the polish of a Kashan or an Isfahan is looking at the wrong carpet.

Colour runs to deep indigo and midnight blue fields set against brick red, gold yellow and soft olive green, with teal and gold picked out in the border; the border colour is usually chosen to differ from the field so that the frame reads clearly. The red of this district is its plainest signature: an orange or rust-toned red rather than the pure red of Kashan and Tabriz. That warmth is what tells the family apart on sight, and it is also what makes these carpets sit easily with terracotta, brass and unfinished wood.

Burgundy deserves a second look on anything from this district. The native reds here are brick and rust, warmed towards orange, so a deep burgundy is rarely the colour that came off the loomSee in the carpet dictionary. The best documented case is the district's Sarouk weaving: carpets shipped to America in the early twentieth century were routinely re-dyed after export to suit a Western taste for dark red, and the treatment is worth suspecting wherever an Arak-district carpet turns up in that shade. The practice belongs to the history of the market rather than to the looms, but it explains a colour that otherwise sits oddly beside the olive and the gold.

Construction across the district follows one pattern: a cotton foundation of warps and wefts carrying a pileSee in the carpet dictionary of woolSee in the carpet dictionary. Cotton is chosen for its rigidity, which holds a large carpet square and keeps it dimensionally stable over decades, while the wool above it takes dye well and wears down slowly. Both knots are found on these looms. The asymmetrical knotSee in the carpet dictionary, generally called the Persian knot, is the central Iranian norm, while the symmetrical or Turkish knotSee in the carpet dictionary turns up regularly in the district's village weaving and in its older pieces, so the knot alone will not settle where a carpet was made.

Knot densitySee in the carpet dictionary is where the village grade separates itself from the workshop weaves of the same district. Antique village carpets of this family are counted at around 116 knots per square inch (KPSI), while a fine Sarouk from the same district sits closer to 225 and the top of the Sarouk range approaches 320. That gap explains the drawing: a high densitySee in the carpet dictionary lets vines curve and flow, whereas a coarser weave has to state the same motif in straight lines and angles. Judge one of these carpets by the confidence of that angular drawing rather than by counting knots.

Sizes tend to the large and the oversize. Carpets of this family were woven to cover the floors of substantial rooms, and pieces over three metres wide and close to five long are normal here rather than exceptional. The allover field helps in a way a medallion design cannot: with no centre to respect, the carpet can be pushed under a table, set off-centre against a wall or run through an open-plan room without the composition looking wrongly placed. Furniture can stand on it without covering the point of the pattern.

Age treats these carpets kindly. The natural dyes of the district mellow rather than hold their original strength, so the indigo softens towards a smoky blue and the rust reds lose their sharpness, and that settling into patina is much of what buyers look for in antique examples. Wear reads gently for the same reason the layout does: with no medallion to damage, a thin patch in an allover field costs the design little. The edges are less forgiving, and on a carpet of this size the long selvedges and the end finishes carry the strain, so those are the parts worth inspecting closely and worth repairing properly.

A Persian rug is an Iranian rug — a rug hand-knottedSee in the carpet dictionary in Iran — and the tradition behind it is the oldest documented anywhere. The earliest surviving carpet, the Pazyryk rugSee 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 dynastySee in the carpet dictionary, from 1501 to 1732, the court promoted weaving alongside painting and calligraphy, and the workshops of Tabriz, HeratSee in the carpet dictionary, Kashan and Kerman produced the masterpieces that now sit in museums. This is when the great central medallionSee 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 dynastySee 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 colours, sizes and patterns. Village rugs such as HerizSee in the carpet dictionary, BakhtiariSee in the carpet dictionary and KarajaSee in the carpet dictionary sit in between, mostly geometric and largely woven from memory. Tribal rugs — Baluch, TurkomanSee in the carpet dictionary, QashqaiSee 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 AbbasiSee in the carpet dictionary palmettes, flowing arabesques, the small repeating Herati patternSee in the carpet dictionary, medallions, garden and tree-of-life compositions. These combine with regional habits into styles a practised 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: madderSee in the carpet dictionary reds, indigo blues, saffron yellows and the soft whites of undyed woolSee in the carpet dictionary, 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 batchesSee in the carpet dictionary — the effect called abrashSee in the carpet dictionary — are a mark of small-batch natural dyeing, not a flaw.

The pileSee in the carpet dictionary is almost always woolSee in the carpet dictionary, and in a Persian wool rug the wool itself decides much of the 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 yarnSee in the carpet dictionary gives a finer, softer thread than machine spinning. Fine pieces add silk highlights to a wool pile, and at the very top sits the Persian silk rug, 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 knotSee in the carpet dictionary, usual in central and eastern Iran, or the symmetric Turkish knotSee in the carpet dictionary, common in the north-west ever since Seljuk weavers introduced it in the eleventh and twelfth centuries. A large rug holds in the region of two million knots and can occupy a weaver for about a year.

Knot densitySee 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 densitySee 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, colour 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 colours settled and their pile supple, often looking better than when they left the loomSee 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.