Shrinkage is the most common quality complaint in textiles — and the most avoidable. A garment that shrinks after one wash destroys trust in the fabric, the garment and the brand. This guide explains why fabric shrinks, which fibres are at risk, how manufacturers prevent it, and how you can test it before committing to bulk.
Why does fabric shrink?
Shrinkage happens when the fibres in a fabric are released from tension and absorb moisture during washing:
- Fibre swelling: moisture makes fibres swell, changing the yarn geometry
- Relaxation: tension set during spinning and weaving releases in the wash
- Heat: high wash or dry temperatures accelerate fibre relaxation
Which fibres shrink most?
| Fibre | Shrinkage Tendency | Why |
|---|---|---|
| Cotton | High | Absorbs moisture strongly; needs preshrinking or sanforizing |
| Viscose (rayon) | High | Swells significantly when wet; wet strength is low |
| Polyester | Very low | Hydrophobic, minimal moisture absorption |
| Wool | High (felting) | Scale structure + agitation causes felting shrinkage |
| T/R blend (65/35) | Low | Polyester stabilises; proper finishing locks dimensions |
The good news for T/R buyers: the polyester component gives the blend a naturally low shrinkage tendency, and correctly finished T/R fabric is dimensionally stable.
How manufacturers prevent shrinkage
1. Preshrinking (pre-shrinkage)
Fabric is relaxed, steamed or compacted after dyeing so that most shrinkage happens at the mill, not in the consumer's wash. Preshrunk T/R fabric typically shows under 3% shrinkage in a home-laundry test.
2. Heat setting for synthetics
Polyester-based fabrics are heat-set at high temperature to stabilise the yarn structure — this locks in dimensions before finishing.
3. Relaxation before finishing
Yarn and greige fabric are allowed to relax under controlled humidity so residual tension is removed gradually.
How to test shrinkage
Testing is simple and standardised. The two most common methods:
- ISO 6330 (international) and AATCC 135 (North America) — home-laundry wash tests
- Test warp and weft separately, in both length and width
How to read the result
| Result | Assessment |
|---|---|
| Under 3% | Good — dimensionally stable |
| 3-5% | Acceptable for many programs with allowance in cutting |
| Over 5% | Problematic — require additional preshrinking or reject |
Also check shrinkage uniformity: if some panels shrink more than others, the garment will skew or twist.
What buyers should do
- Ask for preshrunk finishing in your specification — it is standard for T/R suiting and workwear
- Request a shrinkage test report per lot (AATCC/ISO) from the mill
- Add shrinkage allowance in pattern cutting (typically 2-3% for stable fabrics)
- Wash-test the production sample before bulk — never skip this for first orders
- Agree the tolerance in writing: a common acceptance is ≤3% in both directions
Frequently asked questions
Does T/R fabric shrink?
Correctly finished T/R fabric is preshrunk and dimensionally stable, typically under 3% shrinkage. Unfinished or poorly finished fabric can shrink more.
How can I test shrinkage myself?
Cut a sample, measure warp/weft, wash at the care-labelled temperature, dry, re-measure and calculate the percentage change. A simple 30-minute home test with reliable results.
Does hot water cause more shrinkage?
Yes — higher temperatures accelerate fibre relaxation. Follow care labels and wash at 30-40°C for blended fabrics.
What if my order arrives with high shrinkage?
Check it against the agreed tolerance and the test report. A professional mill will replace defective rolls or agree a credit — which is why testing happens before shipment.
Need T/R yarn or polyester viscose fabric? Send your specification — blend, count, weight and quantity — and get a quotation within one working day. Request a Quote