Why Uniforms Shrink, and How to Prevent It

What causes shrinkage

During weaving and finishing, yarns are held under tension and set in place. When a finished garment then meets heat, water and mechanical agitation in the wash, those yarns relax and draw back towards their natural, untensioned length. That relaxation is what we see as shrinkage.

Three factors drive it: heat, which speeds fibre movement; agitation, which works the yarns loose; and the fibre itself, since some fibres swell far more with water than others.

Why poly-viscose shrinks less than cotton

Cotton is a natural fibre that readily absorbs water. As it swells and is then agitated and dried hot, it can move noticeably, which is why untreated cotton garments are the classic shrinkers. Viscose also absorbs water, so a poly-cotton or high-viscose cloth needs care.

Nearly all our suitings are poly-viscose blends, and the polyester component barely absorbs water and holds its set well. That makes these cloths dimensionally more stable than pure cotton. Cambery, our poly-cotton chambray, carries a cotton share and so benefits most from careful laundering.

How finishing controls it

The best defence is dealt with before the cloth ever reaches a cutting table. In finishing, fabric is relaxed and heat-set so that most of the potential movement is taken out at the mill rather than in the customer's laundry. A pre-shrunk, properly set cloth changes little in normal use.

• Heat-setting stabilises the polyester so it holds its dimensions
• Controlled relaxation removes weaving tension before cut-and-sew
• Consistent finishing keeps shrinkage predictable across a dye-lot
• Blends with a higher polyester share tend to move the least

Laundering to avoid shrinkage

Most residual movement in a finished uniform is triggered by hot washing and hot tumble drying. The table below sets out the main triggers and simple ways to limit each one.

Following these steps keeps a finished uniform close to the size it was cut, and keeps a fleet looking consistent over its life.

Why it matters for pre-stitched uniforms

Shrinkage matters most once cloth becomes a sized garment. If a batch of pre-stitched shirts or trousers moves after the first wash, sleeves ride up, waistbands tighten and a carefully graded size run drifts out of specification. For schools and corporates ordering by size, that means complaints and re-issues.

Choosing a stable poly-viscose cloth, ordering pre-shrunk finishing and giving wearers clear wash care all protect the fit you signed off. Grado 1st, Benzer Special and Sonata are dimensionally stable choices for pre-stitched programmes.

FAQ

Frequently asked questions

Does uniform fabric shrink?

Some movement is possible in any cloth, but a properly finished poly-viscose suiting is dimensionally stable and changes little in normal use. Cotton-rich cloths move more and need more careful washing.

Why does cotton shrink more than poly-viscose?

Cotton absorbs water and swells, so with heat and agitation its yarns relax and draw back. Polyester barely takes up water and holds its set, so poly-viscose blends stay closer to their original size.

Can shrinkage be prevented at the mill?

Yes. Relaxing and heat-setting the cloth in finishing takes out most of the potential movement before it is cut, so a pre-shrunk, well-set fabric changes little afterwards.

How should uniforms be washed to avoid shrinking?

Wash cool to warm on a gentle cycle and dry low or on the line rather than in a hot tumble dryer. Cambery, our poly-cotton chambray, benefits most from this care.