Fabric Shrinkage: What Clothing Brands Should Check Before Production
Understand fabric shrinkage, compare length and width changes, and prepare clear wash-test and sample-approval requirements before garment production.
Fabric shrinkage is a reduction in a material’s dimensions. In a T-shirt, a change in body length can alter where the hem sits, while a change in chest width affects the fit. Length and width may change by different amounts; some measurements can also grow.
Before approving a sample, agree how it will be washed, dried and measured. Those details determine what a reported shrinkage percentage actually tells you.
Why can fabric shrink?
Fabric structure and processing both affect dimensional stability. Cotton knitted fabrics can change as stresses introduced during knitting and processing are released. Dyeing, finishing and garment manufacturing can also influence the result. Fibre composition alone is not enough to predict the final percentage.
Relaxation drying and compaction can reduce residual shrinkage. A pre-shrunk fabric may still change in later washing, so ask for the result under the care conditions intended for your product.
Measure length and width separately
Use this calculation to express a reduction in size:
Shrinkage (%) = (measurement before care − measurement after care) ÷ measurement before care × 100.
| Measurement | Before care | After care | Shrinkage in this example |
|---|---|---|---|
| Body length | 70.0 cm | 67.9 cm | 3.0% |
| Half-chest width | 50.0 cm | 49.5 cm | 1.0% |
Illustrative measurements only. Acceptance limits must be agreed for the product.
In this example, the shirt loses 2.1 cm in length but only 0.5 cm in half-chest width. A single “3% shrinkage” figure would leave the width result unclear. Use the same measurement points each time, including whether chest width is measured flat or as a circumference.
On a laboratory report, shrinkage may appear as a negative dimensional change and growth as a positive change. Check that convention when reading the figures.
What to agree before a wash check
| Item | Decision to record |
|---|---|
| Sample identity | Style, size, version, material reference and relevant production lot |
| Starting state | Whether the sample is before or after any planned garment wash or finishing |
| Measurement method | Named points, units and how each measurement is taken |
| Care procedure | Agreed test method where applicable, washing and drying settings, and number of cycles |
| Assessment state | When and under what conditioning requirements measurements will be taken |
| Acceptance | Permitted dimensional changes and any separate post-care garment measurements |
| Follow-up | Who reviews the result and whether another sample is required |
Drying matters: a result after line drying cannot simply be substituted for one after tumble drying. The cycle count matters too. Keep the procedure with the result so the next sample can be assessed on the same basis.
Fabric testing and garment testing answer different questions
A fabric test assesses the material. A garment check shows how the panels, rib, seams and trims behave once assembled. The neckline or hem may deserve attention even when the main body measurements look acceptable.
AATCC TM135 covers fabrics after home laundering; TM150 addresses garments. Confirm the method and care procedure with the testing provider, particularly for stretch fabrics, as TM150 may not suit some of them. Set the acceptance criteria separately.
Keep shrinkage results alongside any separate colourfastness, print or other performance checks. Our guide to garment sample types explains what the different sample stages are used to confirm.
What should happen if a sample changes too much?
Send the manufacturer the affected measurements, before-and-after values and care procedure. Review the fabric and finishing as well as the pattern before choosing a correction.
A blanket increase to the pattern can create another fit problem. In the example above, adding the same allowance to length and width would ignore their different results. Check the affected dimensions individually, and review a revised sample where needed.
Mark clearly which garment measurements apply before washing and which apply afterwards. If the fabric or finishing changes, review whether the previous result still represents the product.
Use the production brief guide to document the requirements and the sample review guide to organise comments for the next version.
Contact Jiajia Apparel with your design, measurement requirements and intended care instructions to discuss the next sampling step.
Technical references
- CottonWorks: Shrinkage & Skewing — dimensional change and its effects on garment fit.
- Cotton Incorporated: Guide to Improved Shrinkage Performance of Cotton Fabrics — construction and processing factors.
- CottonWorks: Mechanical Finishing — relaxation drying and compaction.
- AATCC TM135 public scope and AATCC TM150 public scope — fabric and garment test scopes.
For fabric-weight decisions, read our GSM fabric guide.
Let’s discuss your collection
Tell us what you are planning to make.