WISTYRIA EDITIONS-Felting Needles. Felting needles are barbed needles used to interlock wool fibers. As the felting needle is moved up and down the barbs on the needles catch the scales of the wool and entangle them creating a material called felt. The 38 gauge star needle is a four sided needle that leaves a smaller hole in the felted surface. It felts slower than the larger gauge triangle needles but the detail is finer. Triangle needles are three sided needles. The 40 gauge is excellent for fine detailing and sculpting. This package contains four 40 gauge triangle needles. Made in USA.