Why Do Clothes Shrink After Washing

Ever notice that your favorite jeans seem a little tighter after you wash them? It’s not just your imagination, clothing does in fact, shrink when wet. Whether you’ve been noticing this for years or just now on a recent laundry cycle, it might be time to learn more about the science and mechanisms behind why your clothes shrink. You can blame it on water or heat, but if you want to understand how they work together even better than before-read on.

Clothes are made of fibers – threads woven together to form fabric. These fibers are mostly cellulose, which is a wood-like material. When you wet them, the fibers get softer – they’re unable to support their own weight as well when they’re wet, so the threads pull apart slightly. This makes your clothes get smaller.

Heat and Fabric

You probably know that heat will make things shrink even more quickly than just water alone. That’s true because the heat begins to break down the glue that holds fabrics together, and it works its way into fibers to make them expand in size as it does so. You can prevent some of this shrinkage by using cold water in the washing machine instead of hot or warm water when you wash your clothes.

Heat and Color

And what about color? Does a load of white clothes shrink differently than a load of red clothes? The answer is yes. It’s about the dye or pigment in the fabric that will be affected by heat – when the dye shrinks, so does the fabric. That’s why you should try washing dark clothes with cold water, and only use hot for lighter colors. The heat will cause more fading over time if it’s used on darker items.

Leathers and textiles will shrink, but their overall size is less of a concern. If you’re disposing of a large or bulky item like a car seat cover, for example, it can be helpful to know that it will shrink before you do this. This will give you a better idea of how much room you actually have to work with.

Shrinking Is More Than Just Physical

The physical shrinking that happens in your wash, and the chemical changes that happen inside the fabric as it dries, are not what causes most of the shrinkage. The main reason that clothes shrink is because of how the fibers are treated when you bathe them in water. The result is a chemical change – called bleaching – in which the fiber gets a shiny surface coating. This makes it more absorbent and breathable after washing, but at the same time it also tends to be less durable than it would be if you just took care of your clothing as you normally would. You can fight the physical shrinking that happens in the wash by using cold water instead of hot or warm water.

The Detergent Reaction

Most laundry detergents contain chemicals that are designed to react with each other. This is how they get your clothes clean, and it’s also how they cause them to shrink. Laundry detergents are basically made up of two different types of chemicals – surfactants and oxidizing agents. When you put these into a washing machine, liquid oxygen is released which causes the fibers to shrink as it does so. The surfactants help this process along by cleaning off dust and dirt particles from fabric so they can combine with the oxygen molecules. These molecules then bind to the surface of your clothing and cause them to shrink. So if you want to stop your clothes from shrinking, avoid using detergents that contain too much oxygen.