Sailors are familiar with the sheet bend , a quick and easy method of joining two ropes which is secure enough for their practical purposes. Bookbinders use the same knot, although some of them may not realize it. To remain successful once tied the sheet bend must remain under constant slight tension.
The method shown below is especially useful in bookcrafts since the "almost finished" thread length can be left quite short, as usually happens in practice. This "old" thread plays a small and passive part in the knot formation. This method also has the advantage that the knot can be tied very close to the working part of the "old" thread.
The start of the knot is shown below. The "old" thread is still threaded through the eye of the needle, and the shaft of the needle lies through the noose of a simple slip knot tied in the "new" thread.
Whilst the "old" thread still in the needle the needle is passed through the loop of a slip knot made at the end of the "new" thread. The slip knot is being used to lassoo the "old" thread, and is gradually tightened. At the same time it is slid as far towards the last hole used by the "old" thread as possible.
When the slip knot is considered close enough to the paper, the hold on the "old" thread can be released.
The next stage involves changing finger grips from that shown above. Leave the "old" thread alone and pinch the loose end of the "new" thread with the fingers of one hand. The picture below shows the "new" thread being held. Hold the working end ~ the spool ~ of the "new" thread with the other hand (not shown in the picture ~ I need one hand for the camera).
A gentle pull on the short and long ends of the "new" thread will cause the noose to choke the "old" thread, pulling it through the noose in such a way that it is unlikely ever to come undone. If your tensions are just right ~ and ears and fingertips finely tuned ~ you can almost feel or hear a click as the old thread is pulled through the noose and securely grabbed tight.
Ideally it looks best if the knot can end up centrally between the two holes. Snip the two ends to be 5mm long ~ and the job is done. The picture, below shows the knot ~ finally tied ~ and close-up to the original hole.
It is not possible to see the finished result in close-up with this, an actual working example. We are preparing a demonstration in more detail should you wish to clarify matters by seeing it in greater close up. Or better still - go and experiment! There is also guidance on tying a simple slip knot .
The method used by weavers to tie their knot is different. It involves wrapping threads around two fingers of one hand and a quick jiggle with the other. No doubt they are able to tie their knot in milliseconds, and with their eyes closed. Please let me know if you can amplify this, preferably with very much slowed-down pictures. It may be a skill that is being lost to future generations.
I am not a sailor. I am sure they also will have one handed, different, but very quick ways of tying sheet bends whilst holding on to the mast ~ in a typhoon ~ with the other hand.