What is excessive shrinkage?#
Excessive shrinkage means the fabric or finished garment changes dimensions after washing by more than the buyer's specified limit. Most shrinkage is a loss of length or width, though some fabrics grow in one direction. Shrinkage beyond the limit makes garments smaller than their size label, and it is a common reason for failed test reports and consumer returns.
Some shrinkage is normal for cotton and other cellulosic fabrics. The defect is shrinkage above the agreed limit. See fabric shrinkage for the background.
What it looks like#
- A test report with dimensional change outside the buyer's limits.
- Garments that are shorter or narrower after the first wash than the size specification.
- Twisted side seams together with shrinkage in knit garments.
- Puckered seams after washing where the fabric shrank but the thread did not.
Where it occurs#
- Cotton single jersey and other cotton knits, especially in length.
- Cotton fleece and French terry.
- Viscose fabrics, which swell and relax strongly in water.
- Garment-washed products where the pattern did not allow for wash shrinkage.
- Synthetic fabrics that were not heat set correctly and shrink in hot washing or drying.
Likely causes#
Fabrics shrink when they are washed after being held in a stretched state. In processing, fabric is pulled lengthwise through machines and often stretched in width on the stenter to reach a target width or GSM. If it is not allowed to relax, or is not mechanically compacted, it will shrink when the consumer washes it.
Machine-related causes#
- Stenter settings: width set wider than the fabric's relaxed width, or too little overfeed, stretches the fabric.
- Compacting: compactors reduce length shrinkage on knits and sanforisers on wovens. If bypassed or poorly set, length shrinkage rises.
- Drying under tension instead of relaxed drying.
- Heat setting of synthetics at too low a temperature or too short a time.
Material-related causes#
- Loose construction: a long stitch length in knits or a low pick density in wovens gives the fabric more room to shrink.
- Yarn type: some yarns (for example, some high-twist or low-quality yarns) shrink more.
- Fiber: viscose and other regenerated fibers can shrink more than cotton in some constructions.
Operator and process-related causes#
- Spreading under tension, so panels are cut stretched and shrink before or after sewing.
- Insufficient relaxation of knit fabric before spreading.
- Tight pressing or steaming that stretches parts.
Method-related causes#
- No bulk shrinkage test before cutting.
- Pattern not adjusted for garment washing.
- Wrong test method: testing with a gentler method than the buyer specifies gives an optimistic result. See dimensional stability testing.
How to confirm the cause#
- Repeat the test with the buyer's exact method, on fabric and on garments.
- Test the fabric lot received and compare with the supplier's pre-shipment test.
- Check finishing records: stenter width, overfeed, compaction, speed, temperature.
- Measure knit stitch length or woven construction against the standard.
- Compare fabric width and GSM with the specification: a fabric finished wider and lighter than standard has usually been stretched.
- Check spreading: relaxation time and spreading tension.
Immediate containment#
- Stop cutting the affected fabric lot.
- Test cut panels and sewn garments to see the extent of the problem.
- Hold finished goods from the lot until test results are known.
- Inform the buyer when shipped or ready goods may be affected, following the agreed process.
Corrective action#
| Cause | Corrective action |
|---|---|
| Fabric stretched in finishing | Reprocess: relax, compact or sanforise, finish at correct width |
| Heat setting insufficient | Reset heat setting parameters for synthetics |
| Loose construction | Correct stitch length or construction for future lots |
| Spreading tension | Relax fabric before spreading; spread without tension |
| Garment wash not allowed for | Adjust pattern with shrinkage allowance; review wash recipe |
| Wrong test method | Test to the buyer's method before approval |
Preventive action#
- Shrinkage test every bulk lot before cutting, to the buyer's method.
- Agree finished width, GSM and shrinkage in the fabric specification.
- Record finishing parameters for good lots and repeat them.
- Wash test first bulk garments.
- For washed garments, set pattern allowances from wash tests. Use the shrinkage calculator.
Inspection notes#
- Measure garments after a test wash, not only before.
- Compare shrinkage results with the buyer's limits for fabric and garment separately; they can differ.
- Record shrinkage by fabric lot so problems can be traced.
Factory checklist#
- Bulk fabric shrinkage tested to the buyer's method before cutting
- Finished width and GSM within specification
- Fabric relaxed before spreading; no spreading tension
- Pattern allowance set for washed garments
- First bulk garments wash tested
- Results recorded by fabric lot
Related guides: spirality, measurement variation.