According to the book "Colored Felt Handbook", wool felt is what the wool "felted". According to the principle, the wool felting process is divided into two types: needle felt and wet felt (P6-P7). The outer surface looks soft and wool, and the surface is covered with many scales that we can't see with the naked eye. When these scales encounter hot water, they will open and erect. If the external force is squeezed, rubbed or rubbed, the scales will be entangled with each other and tightly contracted together to become a felted state. This is the basic principle of "wet felt".
In addition to the wet felt, a special woolen needle can also be used to puncture the wool continuously, which will also entangle the scales on the wool to achieve the felting effect. We call this the "needle felt".
In fact, there are very few books on wool felt making in China. The "Colored Felt Handbook" published by Henan Science and Technology Press (May 2010) is the copyright of Taiwan. The author is Apple Green, very famous. This book is One of the few hand-made books on wool felts is worthy of a handful of sisters who love wool felting. You can buy it on sites like Amazon.