Despite growing up in the 80s and 90s, I can attest that the above is my very FIRST rat tail.
The rat tail is a way of tapering a line’s diameter to a fine tip. In simple terms, a sailmaker separates the three strands of the rope with her fingers. Then, she further pulls each strand into yarns, keeping the three piles separate. Those yarns are each cut down. Then, using beeswax to stick things back together, the strands are reformed and re-twisted.
On our sails, a rat tail is stitched down along the edge of the fabric to secure it in place. The result has a traditional, finely finished look and is a very secure way of holding one end of a bolt rope in place. A bolt rope strengthens the luff edge of a sail. The hardware that holds a sail onto the rigging is on the luff, so a reinforced edge is important.
The rat tail above is attached to a small sampler, not a sail. My co-workers critiqued that the bitter end did not lay quite properly and the whole tail should be two inches longer. Mastering this technique will be a milestone in my apprenticeship, as this kind of finish work happens on our mainsails. Mainsails are usually the most complex sails we make and I just finished building my very first one (with lots of help) last week.