What causes clothes to shrink when you wash them?

is it the heat in the dryer???What causes clothes to shrink when you wash them?
It is the heat in the dryer and also agitation. Wool shrinks due to the agitation in the washer and dryer. The wool gets 'felted' and becomes denser. Cotton is also affected by agitation because the thread that cloth is woven or knitted from has been stretched. Bouncing around in the washer or dryer will cause the fibers to contract, especially cheaper fabrics which were stretched more.What causes clothes to shrink when you wash them?
It depends on the type fabric it is. Agitation and hot water cause some cotton fabrics to shrink the first time they are washed. Denims are the main ones that shrink. They only shrink a certain amount then stop.





If the fabric has a wool content, it will shrink in agitation.





Check the labels on the clothes. See if it has a shrink chart on it. Follow the laundry instructions exactly. If it says dry clean, don't try to save money by tossing it in the washer and dryer. If it says hand wash, it means just that. Cold water for handwash is baby bath warm.
Yes ,the heat almost always shrinks clothing, especially shirts.
In both the washer and the dryer you have to follow the direction tags on the clothes or you can shrink in both. Washing a delicate silk on hot is an obvious. Likewise would be drying same on high for cottons. Follow the clothing tag directions and wash and dry accordingly.