Needle felting is a method of creating felted objects without using water. Boiled wool is a type of felted wool, and is similar to non-woven wool felt. Fulling was a necessary but dirty process where woven wool is felted. Boiled/felted wool is characteristic of the traditional textiles of South America and Tyrolean Austria. A beaver hat is a hat made from felted beaver fur. Felted filters contain randomly placed fibers supported by a woven backing material (scrim). A large demand came from hatters who produced popular beaver felted hats. High energy cleaning techniques such as pulse jet require felted fabrics. The felted material may be finished by fulling. Nonwoven materials are either felted or membrane. Fourth quality is totally unsalvageable, and consists of the larger felted bits or stained fibre. They are followed by felted green seedpods containing pea-like seeds. Their upper side is dark green and their underside is a grayish green and felted. The roots are covered in hairs to which fine sand adheres creating a felted appearance. Only certain types of fiber can be wet felted successfully.