What's the difference between wool and acrylic and which is warmer?

I want to buy a hat for the colder weather and don't know what material to choose from. I see some are 100 percent wool or acrylic and some are 50/50.





Which material is better for warmth?





I don't know what category this fits in.What's the difference between wool and acrylic and which is warmer?
Wool is a natural fiber from sheep. Acrylic is synthetic.





The only downside of wool is that it can shrink if it gets wet (usually wet and warm, then it shrinks). Acrylic is not very good though. The problem with acrylic is that it tends to hold moisture and body heat in too much...so you end-up sweating. I have som acrylic shirts (that looks like flannel), but they are nasty to wear, as they don't ';breath'; (release persperation) like natural fibers such as cotton or wool.





A 50/50 blend is probably best. The wool won't shrink as much and you will still have some breathability (excess persperation evaporating) with the hat.What's the difference between wool and acrylic and which is warmer?
im not really sure how to explain the difference but i think wool is warmer then again thats just me