Most people probably consider felt as a type of cloth - smoother and tougher than cotton or woolen fabric, but cloth nonetheless. But really there is little similarity. Unlike cloth, felt is made up of many short, single animal fibres. These fibres interlock; they have a natural tendency to "crawl" and twist when kneaded and manipulated in hot water and steam. Pressure, heat and water are used throughout the hat making process.Felt is the strongest natural fabric produced, because every fibre is interlocked in every direction with a number of other fibres. All other fabrics are made of fibres which are first twisted into threads and then woven by hand or machine. Because these threads are always woven in either right-angled or parallel lines, the woven fabric can be torn along a straight line.
Since felt does not have the bulk of twisted threads that woven fabrics do, it is also the smoothest fabric known.Felt is the lightest fabric known because few fibres are required to provide the strength necessary. For the same reason felt is the most resilient of fabrics.
It's also more impervious to water than any other fabric.
This is for two reasons: Firstly, the fibres interlock closely making them less absorbent. Secondly, the animal fibrers themselves do not soak up moisture.Most hats are manufactured from a mixture of furs from beavers, hares and rabbits. These are selected and used in percentages to suit the makers' preferences. Very fine hats are produced from these mixtures.
The largest hat market is those made from rabbit fur. Rabbit skins are obtained from many countries - England, Australia, New Zealand, many parts of the Eurpoean continent, China and South America. English skins are preferred by some manufacturers, but Australian skins rank highly.The fur used in manufacturing felt hats is the downy-under-fur of these animals, not the long, coarse hair commonly called fur. This under-fur has tiny barb-like projections on the surface of each fibre and these barbs lock the fibres to make strong felt.
The fur is graded (cheeks, flanks, sides, centre-backs or entire) and then packed into different bags for storage. Fur from the centre-back is the choicest fur, the fur from the sides is the poorer quality. A good blend is a proper combination of furs, skillfully selected by the hatter.