It's Your Bees Wax

Beeswax is a vital, natural tool for needlepoint, embroidery, and sewing, used to coat thread to prevent fraying, reduce tangles, and add strength. By pulling thread across the wax, it glides through fabric more easily, reducing hand fatigue and making stitching smoother. 

This beeswax is especially useful for Metallics fibers.

Usage:

Gently pull the end of the thread over or through the beeswax, often between the thumb and wax, then run it through fingers to remove excess.  It will keep the end of your thread from fraying.