"Craft" may be defined as the making of something useful or decorative from raw materials. During the great age of sail some craft-minded seafarers expanded on their necessary skill of tying knots and spent their spare time making useful and decorative items either for themselves or as gifts for loved ones ashore. This art form is commonly referred to as "marlingspike knot work" or "marlingspike seamanship." This is because a tool called a marlingspike (see photo) is usually required to perform the work.
The possibilities were only limited by the materials at hand, available tools, and more importantly, the imagination and skills of the sailor.
Historically, the craft was passed on via the tradition of time the master spent with the apprentice or journeyman. Much of this has been lost over the years as professions and trades have changed. The skills involved are hard to gain from reading a book and are best learned by spending some quality time with a person experienced in knot tying, say 10-20 years or so.
Common raw materials available to the sailor were the scraps of old, weathered rope or worn lines and "stuff" that became available when a piece of rigging was replaced. Some sailors would take a share of these lines (if they were so entitled) and recycle the material by untwisting the fibers and re-rolling them into what were called ‘nettles’ (similar to a long shoelace.) They would then use these small pieces of handmade cord to tie decorative or utilitarian items.
As the age of sail has passed, this craft has all but disappeared. The passing on of knowledge, skills and abilities via publications and the internet has helped to both teach and preserve this art.
Modern materials and tooling have also changed the art. Knot tyers are (for the most part) no longer recycling fibers. Cotton and synthetic cords are now cheap and readily available. Modern materials range from fine threads and the monofilament fibers used by fishermen to high-quality braided cords and large diameter ropes and specialty lines used by mariners, rescue teams, rock climbers, tree surgeons, etc. There are many low-cost choices of high-quality lines or ‘stuff’ that are available today for tying of knots for both practical and ornamental purposes.
Specific interests of knot tyers range from the practical interest in the strength of a knot or the methods by which they can be tied in a speedy or perhaps one-handed manner. Some are interested in the application of these ‘practical’ knots while other knot tyers are interested in only the decorative or ornamental uses of knots. An experienced knot tyer may be very capable of tying a decorative knot and have little skill (or interest) in tying more than a few practical knots, while some have an interest in only the speedy tying of practical knots. This diversity of interests in the various specific aspects of the craft is wonderful and provides the opportunity for exchanges on many levels.
Some specific families of knots such as the "turk's head" knot and "bends" (knots that join two lines or ropes) have so many interesting aspects that groups of people have become interested in those specific knots.
A hearty stew of inspiration, instruction, context and history may be found in Clifford W. Ashley's remarkable work entitled "The Ashley Book of Knots". This book is a must-have for the knot tyer's reference collection and is available via you local bookseller. Don't let the price scare you away; think of it as a lifetime investment.
Many fine examples of decorative or ornate knot work survive to this day in museums and private collections. The craft was, and is yet, limited only by the skills of the tyer, their imagination and material. At present, much of the work produced by current knot tyers may be more aptly described as 'sculpture' rather than 'knot tying.'
The preservation of this craft is being sought by the International Guild of Knot Tyers. This group seeks to preserve, expand and explore the arts and techniques involved in the craft by teaching and making the public aware of the craft.