system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: why's it when you put some wet fabric, e.g. a towel, on a radiator, it dries all stiff and crusty?
gpt
The little fabric bits on the outside of a towel stick together when wet and tend to remain stuck (hence crunchy) when it is air-dried without air movement. A tumble dryer circulates warm air as the towel dries, which tends to separate the stuck fabric bits and the material feels more fluffy to touch.