Before anyone washes your kilim, get a tape measure and write down five numbers. The length down each side, the width across each end, and the distance between opposite corners. Then do the second diagonal and make it six.

Those numbers settle arguments. They tell you whether the rug has shrunk and how far a good workshop can bring it back. Most customers who ring us about a kilim that came back small from another cleaner have no idea what size it was before, and a few centimetres of memory against a few centimetres of tape is a conversation nobody wins.

What Makes a Kilim Shrink When It Gets Wet?

A kilim is a flatweave. It has no knotted pile, only a set of warp threads running the length of the rug and wool weft threads packed tightly across them, back and forth, so densely that the warps disappear. The pattern you see is entirely weft. The structure holding it together is entirely warp.

Water gets into both. Fibres swell as they absorb it, and as a yarn swells in thickness it pulls in along its length. When it dries under no tension, it doesn’t necessarily return to where it was.

Cotton Warps and Wool Wefts

The trouble usually starts with the warps.

Older Anatolian kilims were often woven on wool or goat-hair warps, and wool warps under wool wefts tend to move together evenly when wet. A great many kilims made for the export market over the last few decades use cotton warps, which are cheaper and more consistent to weave with. Cotton shrinks more than wool when soaked, and it does so along the length of the rug. The wool wefts, meanwhile, relax and can spread slightly. The result is a kilim that loses length faster than width, sometimes by five or six centimetres on a two-metre piece.

Hot water and tumble drying both make it worse. So does a long soak.

A power-loomed kilim-style rug from a furniture chain is a different animal. It’s usually polypropylene or a polyester blend woven by machine under even tension, and it barely moves in water at all. Its problems when washed are fading and a flattened, shiny surface.

Why Does a Kilim Go Out of Square as Well as Shrinking?

Because it was probably never square in the first place.

A kilim is woven by hand on a loom, often by more than one weaver, and the tension on the warps changes as the work goes on. One side gets beaten down harder than the other. A weaver who stops for a season leaves a slight change in the weave where she started again. Warps from different batches of yarn shrink by different amounts. None of that shows much when a new rug is lying flat on a shop floor. Soak it, and every difference in tension comes out at once. The long sides stop running parallel and the diagonals no longer match.

If anything, a kilim that comes out of a wash slightly irregular is showing you how it was made.

The Dealer’s Stretch

Here’s the part the rug trade doesn’t advertise. Many kilims are washed and stretched square before sale – pinned out wet on a frame or a floor and left to dry under tension, so they lie straight and flat in the showroom. That’s a legitimate finishing step. But it’s temporary. The yarn holds that stretched shape only until it gets thoroughly wet again, and then it goes back towards the shape the weaving gave it.

A customer from East Dulwich brought us a kilim she’d bought from a dealer on Portobello Road a few years earlier. It had been beautifully square in the shop. After a wash at a laundry it had a four-centimetre difference between its diagonals. She blamed the laundry. The laundry was only partly to blame – they’d washed it too hot and dried it on a line, which didn’t help – but most of that shape had been waiting inside the rug since the day she bought it.

I think dealers who sell a stretched kilim should tell the buyer it will move the first time it’s washed. Hardly any do.

How Should a Kilim Be Washed to Keep Its Shape?

Cold, and measured from start to finish.

Everything starts with the numbers. We measure all four sides and both diagonals and photograph the rug laid flat on the workshop floor. Old repairs and weak slits get noted on the job sheet. Then we check the fringe to see what the warps are made of, since that tells us how much movement to expect.

Next, a dye test. Many Turkish kilims carry strong reds and oranges, and on some modern pieces those dyes aren’t stable. A damp white cloth pressed hard on each colour for a minute will show whether any comes away. If it does, the wash changes completely, with a shorter contact time and a dye-fixing acid rinse ready.

Before any water goes on, dry soil comes out. A kilim holds a surprising amount of grit between its tightly packed wefts, and wet grit becomes mud. We dust it from the back on a vibrating dusting machine or by beating it on a frame, then vacuum both sides.

The wash itself is done flat on the workshop floor, with cool water and a gentle wool detergent, worked in with soft brushes along the direction of the warps. Agitation is kept to a minimum, because wool fibres that are rubbed hard while wet start to felt and tighten, and felting can’t be undone. The rinse is thorough, with a mild acid rinse at the end to leave the wool slightly acidic and help hold any unstable dye.

Then the water comes out as quickly as possible. A kilim left heavy with water for hours gives its warps time to shrink. We use a squeegee and a wet vacuum across the whole surface, sometimes a rug centrifuge for a sturdy piece, to take it from soaking to barely damp within minutes.

On a job for a customer in Stoke Newington, a two-and-a-half-metre Konya kilim with cotton warps came off the wash floor three centimetres shorter than its original length. After blocking and drying it was eight millimetres shorter, and square to within half a centimetre across the diagonals.

Blocking a Kilim While It Dries

Blocking is how that length gets back. The damp kilim is laid on a board or a clean floor and gently eased back towards its measured dimensions, a few millimetres at a time, working out from the centre. It’s then held there with rust-proof stainless pins or weights along the edges while it dries, with air movers running across it so it dries within hours. We check the diagonals several times as it goes, and nudge the pins when one corner starts to creep.

If anything, blocking takes longer than the wash itself.

Can a Shrunken Kilim Be Stretched Back?

Partly, and it depends on how much it moved and how old it is.

A kilim that came back a few centimetres short from a careless wash can usually be rewet, blocked and dried back to within a centimetre or two of its original size. The cotton warps haven’t been damaged. They’ve only contracted, and controlled tension while drying will lengthen them again.

What can’t be recovered is felting. A kilim that was scrubbed hard or put through a washing machine has wefts that have locked together, and no amount of pinning will open them back up. The rug feels thicker and stiffer, and the pattern looks slightly blurred at the edges of each colour.

If you’re already in dispute with a previous cleaner, the recovery is worth attempting before anyone talks about compensation. A kilim that has been blocked back to within a centimetre of its old size is a much smaller grievance than one lying crooked on the floor, and if anything, cleaners are more willing to pay for a re-block than to argue about what size the rug used to be. Bring the receipt from the dealer if you still have it. Many list dimensions, and those are the nearest thing to the six numbers most people never wrote down. They’re rarely exact, since dealers round to the nearest five centimetres, but a dealer’s receipt beats memory.

When the Slits Start to Open

Most Anatolian kilims are woven with slits where two colours meet in a vertical line, and those slits are the weak points. Stretch an old kilim too hard and the slits open into gaps, sometimes tearing along the length. On anything with visible age, we’d rather leave a rug a centimetre short and irregular than risk splitting it to make the numbers match. Any gaps that appear during blocking need hand-stitching before the kilim goes home.

Does Every Kilim Need Washing?

Far less often than people think.

A kilim on a living room floor in a house without dogs or small children can often go ten years between full washes. Regular vacuuming on both sides and a gentle beating in the garden once a year do most of the work. Fresh spills can be blotted and spot cleaned where they happen.

Full immersion washing is for a kilim that’s heavily soiled or has been flooded. For one that just looks a bit dull, I tell the customer to take it outside, hang it over a washing line on a dry day, and give it a good beating with a carpet beater. They’re generally surprised how much comes out.

A Check Before You Book

Look at the fringe. If the warps are bright white and slightly shiny, they’re almost certainly cotton, and you should ask the cleaner exactly how they plan to control shrinkage. If the warps are off-white or goat-hair grey, the kilim should move less.

A customer in Richmond did this with his hallway kilim and rang back to cancel. It had grey goat-hair warps, a slight lean to the left, and forty years of beating on a washing line behind it.