Splitting a single ply thread into two strands, allows space for materials such as deer hair, hackle barbs, and dubbing to be placed between the strands. once the materials is inserted, spin the bobbin holder to tighten the thread around the materials, then rap it around the hook shank. Splitting a thread has usually been done with a very pointed thin needle. The thread is flattened with the help of one's finger nail, and then the needle is pushed through the thread, of course if you can hit it. And the thinner the thread, the harder it is to hit it.
With a SMHAEN Thread Splitter, this is no longer a problem. and it does not matter if it is a thick or thin thread. The SMHAEN thread splitter does both easily. a smooth edge and a small knob on the end of the needle make it possible to split the thread. Flatten the thread on the shaft of the needle. Slide the thread to the knob at the end of the needle and allow the small edge to grip the individual fibers. Pull back slightly to allow the fibers to separate, then push the round knob through to split the thread into two strands.