it's not a common practice to put a hat on a clothesline to dry it. Typically, clotheslines are used to hang and dry clothes such as shirts, pants, socks, and towels. Hats, especially those made of delicate materials like wool or straw, may not be suitable for hanging on a clothesline as they could lose their shape or become misshapen due to the weight of the water.
Instead, hats are usually dried using alternative methods, such as placing them on a flat surface or using a hat form to maintain their shape while they dry. Some people may even choose to hand-wash their hats and then allow them to air dry indoors or outdoors on a clean, dry towel. If necessary, they might reshape the hat gently with their hands while it's still damp to restore its original form.
It's always a good idea to refer to the care instructions specific to each hat's material to ensure it is dried in the best possible way. Keep in mind that clothing care practices can vary depending on cultural norms, personal preferences, and the type of hat or garment in question.