According to the book "Quick Class of Wool Felting Hands", wool felting is the thing after wool felting. According to different principles, wool felting process can be divided into needle felting and wet felting (P6-P7). The surface of the wool, which looks delicate, is covered with many scales that we can't see with the naked eye. When these scales meet hot water, they will open and stand up. If extruded, rubbed and rubbed by external forces, the scales will tangle with each other and contract tightly together to form a felting state, which is the basic principle of "wet felting".
In addition to wet felt, you can also use a special wool stabbing needle, constantly stabbing wool, the same will make the scales on wool intertwined, to achieve felting effect, we call this practice "needle felt".