A towel goes flat and thin long before it wears out. The loops are still there, they are simply coated, matted and stuck down, and a coated loop cannot hold water or air. Most towels that feel finished are clogged with softener and detergent residue, and a stripping wash brings a surprising number of them back.
What loft is and why towels go flat and thin
Terry towelling is a woven ground cloth with thousands of loops standing up off it.
The loops do two jobs. They trap air, which is what makes a towel feel thick, and they present an enormous surface area of cotton for water to wick into.
Absorbency is capillary action. Water climbs into the spaces between fibres, and the fibre has to be clean and open for that to happen.
A towel that has gone flat and thin has loops lying down and stuck to each other, so the trapped air is gone and the surface area collapses.
It feels thinner because it is thinner. The pile has been compressed, not removed.
That is the useful part. Compressed and coated is reversible, and worn away is not.
Fabric softener is the usual cause
Softener works by depositing a thin waxy layer over the fibre. The softness you feel is a coating rather than any change in the cotton itself.
That coating is water repellent by design, which is directly opposed to the one thing a towel is for.
It builds up. Each wash adds a little more, and after a few months the loops are lightly glued to each other, the towel goes flat and thin, and it pushes water around instead of taking it in.
Dryer sheets do the same job by a different route, transferring the coating with heat inside the drum.
A new towel that stops absorbing after a month has almost always met a softener.
The fix is simple and unwelcome, which is to stop using it on towels at all. Towels do not want softening, they want to be clean and shaken out.
Detergent residue does it too
Detergent that does not rinse away leaves its own film, and that one is not soft. It is slightly tacky and it holds on to soil.
Too much detergent is the usual reason. Towels are absorbent by nature, and a heavy dose in a low water wash never fully leaves the cotton.
An overloaded drum is the other reason. Towels swell enormously once wet, and a drum that looked reasonable when dry is a solid mass with water in it.
Hard water adds a mineral deposit on top, which stiffens the pile and leaves a towel feeling scratchy and flat and thin at the same time.
The tell is a towel that smells faintly of detergent when dry, or that dries board stiff on a line rather than merely firm.
Over drying scorches the fibre
There is a point in a dryer cycle where the towel is dry, and every minute beyond it is damage.
Cotton fibre needs a little residual moisture to stay flexible. Pushed past that, the fibre goes brittle and the tips of the loops snap off.
The lint in the filter is that broken fibre. A load of towels producing a thick mat of lint every time is a load being over dried.
High heat also bakes in whatever residue is already sitting on the fibre, which makes the coating harder to strip out later.
Medium heat, stopping while the towels are just short of fully dry, is better for the pile and faster as well.
Finish them on a rail for twenty minutes if they come out slightly damp.
A stripping wash to reset them
Stripping means removing accumulated coating rather than removing dirt, and it is done on towels that are already clean.
Run the load through a hot wash with no detergent at all and half a cup of washing soda. This is the cycle that lifts most of the residue and the mineral deposit off towels that have gone flat and thin.
Follow with a second hot cycle carrying a cup of white vinegar and nothing else, which cuts what the alkaline step left behind.
Keep the two apart. Vinegar together with detergent or with washing soda in the same cycle cancels out and achieves nothing.
Finish with a plain hot rinse so nothing at all is left sitting in the fibre.
Do it as a small load so the towels have room to move. A stripping wash in a packed drum repeats the failure that caused the problem.
Expect the first cycle to run grey. That is what was in the loops.
Shake it out before it goes in the dryer
This takes thirty seconds and it does more than any product on a shelf.
A towel leaves a spin cycle compressed into a folded slab with the loops pressed flat against each other.
Loops that go into a dryer stuck together dry stuck together, and heat sets them in that position.
Take each towel by two corners and snap it out hard a couple of times on the way into the machine. You can feel the pile lift.
Dry with room to tumble. A packed dryer cannot separate anything, and towels that cannot move come out damp and matted at once.
Dryer balls help by keeping the load moving and breaking folded slabs apart partway through.
Shake them again coming out, and fold them rather than cramming them onto a shelf.
Rescue or retire
Hold the towel up against a window. Even light coming through the ground cloth means the pile is intact and the towel is worth stripping.
Bright patches where you can make out the shape of the window mean the ground cloth is thinning and the towel is done.
Run a hand across the pile. Loops matted flat but present will come back. Areas where the loops have been rubbed off down to the weave will not.
Check the band where a towel hangs over a rail, which wears first, and the hems and selvedges, which fray first.
A towel that is stiff, dull and unabsorbent but has full pile is a stripping job. A towel that is soft, floppy, flat and thin with the ground cloth showing through is a rag.
Retiring one is no waste. Cut it down into cleaning cloths and it will outlast anything bought for the purpose.
The Durham part
Humid summers are the practical difficulty with towels here. A bath towel hung on a rail in July dries slowly, and a towel that never fully dries between uses picks up a stale smell that comes back every time it gets wet again.
Spreading a towel out to its full width rather than folding it over a rail doubles the exposed surface and makes a real difference across a summer. A hook is the worst option in the room.
Pollen season is the other one. For several weeks the air carries a heavy yellow load, and anything dried outdoors comes back in with pollen worked down into the pile, which is a poor outcome for a towel in particular.
Mild winters mean the house runs less heat and stays less dry than it would in a cold climate, so indoor drying is slower year round than people expect. Moving air does more than warmth, so a fan or an open window beats turning the thermostat up.
Where a stripping wash actually works
Stripping towels needs hot water, room in the drum, and a rinse that carries residue out of the building.
The machines at our self-service laundry on Guess Road run a small load of towels in enough water to move freely, and the drum size means a full set of bath sheets tumbles instead of packing into a solid mass.
Our machines and the store are cleaned daily.
Nou wash-dry-fold service covers the everyday laundry.
For general guidance, The American Cleaning Institute publishes a fabric care guide that is a useful cross-check.
The short version
Towels go flat and thin because the loops get coated and matted rather than worn away, which means most of them can be brought back. Stop using fabric softener and dryer sheets on towels, cut the detergent dose, and stop overloading the drum, since wet towels swell and a packed load never rinses. Strip them with a hot wash using washing soda and no detergent, then a second hot cycle with white vinegar alone, never both together. Dry on medium heat and stop while they are just short of dry, because over drying snaps the fibre. Snap each towel out hard before it goes into the dryer. Retire the ones with the ground cloth showing through.
WaveMAX Durham is at 3222 Guess Road, easy to reach from Durham and the surrounding area. If you have a load that will not fit at home, call us at 919-748-3180.