Needle felting is a process which uses barbed needles to interlock wool fibers to form a more condensed material. Wool fibers have scales which when rubbed against each other catch and lock into place to create this denser material called felt. Felting needles are used to entangle the fibers. As the felting needle is moved up and down, the barbs on the needles catch the scales of the wool and entangle them into place.

Wet Felting utilizes friction, soap, and water to transform wool fibers into felt. The combination of hot water and soap alters the wool's pH, enabling the scales on the fibers to open up and interlock.