Pay for a repair when the fix costs less than a third of replacing the garment, and mend it yourself when the damage is in a seam or a rib. Most holes in knitwear fall into the first category, most split seams into the second, and almost nothing falls into the third, which is why a mended sweater outlives three new ones.
Knits and woven cloth fail differently
In a knit, the yarn runs in continuous loops, so a hole is a row of broken loops waiting to be rebuilt. That is why darning works: you are re-creating structure that already surrounds the gap. In woven cloth the threads are interlaced rather than looped, so a hole means the warp and weft have been cut, and rebuilding them by hand is a specialist job called reweaving.
Two hand methods cover most knitwear. Swiss darning, also called duplicate stitch, follows the existing stitches one by one and rebuilds the missing column exactly, which makes it near-invisible on a plain knit or a rib. Woven darning stretched over a mushroom lays new threads across the hole in both directions, which is faster, stronger on a large hole, and the natural place for a contrasting color if you want the mend to be seen.
Match the yarn before you match anything else. A mending wool one ply finer than the garment blends into the surface, while a thicker one sits proud and pulls the surrounding stitches. For cashmere, use a lace-weight yarn rather than sewing thread, which has no give and will cut through the loops it is supposed to hold.
What it costs, and when to pay
Repair vs. replacement (cost estimates)
| Damage | The fix | Typical cost | Worth it when |
|---|---|---|---|
| Moth hole in a knit, pea-sized | Woven or Swiss darning | $15 to $30 per hole | A replacement would cost $80 or more |
| Small hole in a shirt or cotton | A patch from the inside | Nothing to $12 | The shirt is sound and fits |
| Worn elbows on a wool sweater | Reweaving, or contrast patches | $45 to $90 | The knit is heavy enough to carry a patch |
| Ladder in fine merino or cashmere | Invisible reweaving, by a specialist | $40 to $100 and up | Rarely, unless the piece is loved |
| Split seam at the armpit | A hand stitch along the old seam | Your time, around ten minutes | Always. It is the cheapest repair there is |
| Felted or shrunken knit | Nothing. The fiber has locked | None | Never. Felting is not reversible |
Batch the work rather than sending one garment at a time. Repair services often charge less per hole when you send several at once, because the setup costs the same. If you own four sweaters with moth damage, one appointment can cost far less than four. Know your target: the larvae of the common clothes moth feed on wool and other animal fibers, which is why the holes cluster in knitwear.
Mending it yourself, in four steps
- 1
Stop the run before you start
Catch the loose loops with a pin or a contrast thread so they cannot unravel further. A hole that grows while you find your needle becomes a mend three times the size.
- 2
Stretch the area over a form
A darning mushroom, an egg or a rolled towel holds the fabric flat without pulling it out of shape. The mend takes the shape it is held in, so a loose hold leaves a baggy patch.
- 3
Rebuild in the direction of the knit
Follow the loops that remain rather than inventing a grid. Work one row at a time, leaving the stitches just slack enough that the mend moves with the garment instead of fighting it.
- 4
Press and check under tension
Steam the area and gently stretch it. A mend that puckers when the garment is worn was worked too tight, and it is easier to adjust before the thread is buried.
Six tools for a mending tin
None of this needs a machine, and the whole kit costs less than one professional repair. Prices are shown only where we confirmed them on the brand or retailer page in Oct 2026.
Start hereClover
Darning mushroom, beech
Holds the fabric under a light tension, which is the difference between a mend that sits flat and one that puckers for the life of the garment.
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Woolovers
Mending wool, lambswool, 25g
One ply finer than the garment blends invisibly, and a natural shade takes a dye better than a synthetic blend if you need to match a color exactly.
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Olympus
Sashiko needle and thread set
The traditional Japanese kit: longer needles and stout cotton thread, built for reinforcing a worn area with rows of running stitch rather than hiding it.
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Speedweve
14-hook darning loom
A small metal loom that holds the warp threads for you, which turns a fiddly sock heel into twenty minutes of work. It is the fastest route on anything with a dense knit.
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Clover
Needle felting starter kit
Felting wool into a hole fills it with fiber rather than re-creating the stitch, which suits thick lambswool and hides well on a textured knit. It is a patch, not a repair.
Check priceJohn Lewis
Darning needles, pack of six
A blunt tip finds the gap between loops instead of splitting them, which matters more in knitwear than thread choice does. Large eyes take mending wool without fraying it.
Check priceWhen a repair is not worth making
Walk away from a garment whose fiber has already failed. A sweater that has felted in the wash has locked its scales permanently, and a knit that snaps when you tug it has lost its elasticity rather than its yarn. The same applies to cotton that tears along a fold line, which has usually been weakened by years of light and washing rather than damaged in one place.
The honest test is a gentle pull at the edge of the damage. If the surrounding stitches hold, the garment has years left and the mend will take. If the whole area gives, you are repairing a structure that has already gone, and the money is better spent on the replacement.
