Why and how do clothes shrink in the dryer?

Question

Also, why do some clothes need to be dry-cleaned?

Answer 1

clothes made with cotton shrink. Only if the manufactures would pre-shrink before the clothes were made

Answer 2

It's all about fibers...those that are more delicate need to be dry cleaned. You need to read your cleaning labels more closely. They tell you whether the piece should be dryed on high, medium or low heat or maybe dryed laying flat. When you follow the directions, you shouldn't have shrinkage.