Boiled wool originated in Scandinavia where it was invented to keep out the cold. It is a woolen fabric which is felted in boiling water. It has a supple and soft texture which doesn't fray, so needs no hemmimg. It also doesn't pill or crease. Boiled wool should not be confused with felt. There are two types of felt - a non-woven fabric generally made of poor quality synthetic fibres, or a natural fabric obtained from animal hair.