Why Custom Clothing Shrinks — and How to Avoid It

Cotton shrinks because knitting stretches the yarn under tension, and the first wash lets those fibres relax back. Pre-shrunk fabric has been through that process during manufacture, so it moves far less afterwards. Washing cool and drying gently prevents most of the remaining shrinkage.

What Is Actually Happening

During knitting and finishing, yarn is held under tension, which stretches the fabric beyond its natural relaxed state. Heat and moisture release that tension, and the fibres contract towards where they wanted to sit all along. That is why the change is most dramatic on the first wash and much smaller afterwards — the fabric is not continuously shrinking, it is settling once.

Polyester barely does this, because synthetic fibres are heat-set during manufacture and are dimensionally stable. This is a large part of why poly-cotton blends are standard for workwear: a uniform that changes size after its first hot wash is a real operational problem.

What Reduces It

Some of this is specification and some is care.

• Pre-shrunk or garment-washed fabric has already been through a controlled shrink during manufacture, so residual movement is much smaller.
• Poly-cotton blends shrink substantially less than pure cotton, in proportion to their polyester content.
• Higher-quality cotton — ringspun and combed — is generally more stable than coarse carded cotton, though it still shrinks.
• Heavier fabrics tend to be more dimensionally stable than very light ones.

Washing and Drying

Heat is the main driver, and tumble drying does more damage than washing. Washing at 30 degrees and drying flat or on a low setting will keep most cotton garments close to their original size indefinitely. Hot washes followed by hot tumble drying will shrink almost any cotton garment noticeably. This matters doubly for printed garments, where high heat also shortens the life of the print.

“"Most shrinkage complaints are really tumble-dryer complaints."”

Ordering to Allow for It

If you are ordering pure cotton that is not pre-shrunk and it will be washed hot — team kit, uniform, anything institutional — factor a small allowance into your size decisions rather than ordering exactly to measurement. For workwear specifically, the more robust answer is to specify a poly-cotton blend at the outset and remove the problem rather than manage it.

Communicating Care

If you are selling garments, a simple care instruction — wash cool, dry low, iron inside out, do not iron directly on the print — prevents most of the complaints you would otherwise field. It costs nothing to include and protects both the fit and the decoration. Orders start at 50 pieces with mixed sizes, so testing how a fabric behaves through a wash cycle before scaling to volume is straightforward, and the free instant price calculator lets you compare fabrics across your quantity.