Cotton is an extremely versatile material; it is comfortable and breathable on the skin and extremely hardwearing. But like many natural materials, it can shrink when subjected to temperature extremes, or when having to endure washing machines and tumble dryers often. So what is the best way to wash your cotton pyjamas and avoid shrinking them?

Why do cotton pyjamas – and other cotton garments – shrink when washing? Most natural fabrics (wool, silk, cotton) can shrink in two ways: fibre shrinkage (the natural response for fibres that are subjected to heat that is involved with washing and drying) and fabric shrinkage. This is when tension has to be applied to the fabric during manufacturing, making it strong and taut, that is then released when exposed to the heat if washing and drying causing the clothing to shrink.

The best way to avoid shrinkage is to wash by hand, as heat and friction are the catalysts for any shrinkage. The safest way is to wash in cool water with a gentle detergent (that is designed for hand washing), carefully pressing the detergent through the garment and rubbing any stains from the fabric. Empty the water and refill with clean cool water and rinse. Continue this process for each piece of clothing. For best results, then air dry on a clothesline, putting on clothes hangers to retain shape.

No need to panic if you don’t have time to hand wash your cotton pyjamas! Most washing machines tend to have a setting that can help cotton items from shrinking. If in doubt, use the 30° or ‘cold’ setting, and set the cycle setting to ‘delicate’. Fabric conditioner can help to avoid any wrinkles or shrinkage as it helps to smooth the fibres of the garment, reducing friction when washing – the main cause of cotton shrinkage. When the cycle has finished, remove from the machine, shake gently and hang up to air dry. If this is inside, choose a room where the air can circulate easily (and open a window).

The main things that cause shrinkage to your cotton items are heat and friction, so unfortunately it’s best to avoid the tumble dryer. If you really feel that you need to use the dryer, it’s best to wash and prepare your clothes that they have the least chance of shrinking when in the dryer. Use a fabric conditioner, and wash in a cool temperature. Set your tumble dryer to the lowest heat possible, as a high heat will make the cotton fibres contract – and shrink.

Technically, no, and this is the best option to ensure there is no shrinkage. Your cotton items are more likely to shrink if washed in water. There is a small chance that the cotton fabric can shrink during the dry cleaning process, but this is only of the dry cleaning machines have not been maintained properly or of they happen to malfunction during the cleaning process – but this is very rare!

Cotton is one of the most hardy of all fabric clothing materials, can withstand daily wear and is a perfect choice for pyjamas. Always check the label before washing, and you should be able to avoid shrinkage.