To learn to read loom instructions is to prepare to participate in one of the oldest crafts in the history of humans. No matter the relative complexity of a weaving loom or a weaving pattern, the basic function of most types of looms is essentially the same, as is the vocabulary surrounding looms and most types of weaving. Success in reading loom instructions and weaving patterns will depend on learning the names and functions of each of the elements of your loom and weaving equipment.
The basic function of a loom is to hold a series of parallel threads, called a warp, on a frame under tension while other threads, called a weft, are woven through them and will create your weaving projects. The basic treadle, or floor, loom usually has either two or four harnesses, which are attached to heddles, a system of loops through which the warp is passed. After being threaded through the heddles, the warp threads are stretched between two beams and held in tension by a ratchet and pawl system on the beams.
The warp beam holds the warp, and a raddle — a long, flat piece of wood with pins to evenly space the warp — creates an even plane of warp thread that is secured to the cloth beam. As weaving progresses, the woven cloth or rug is wound on the cloth beam as additional warp thread is released from the warp beam.
Foot pedals called treadles are connected — by a system of cords and pulleys — to the harnesses and, when depressed, a treadle causes a harness to be raised; this pulls the strands of warp threaded through that particular heddle to rise, forming a shed or opening below the raised warp strands and above the remainder. A shuttle, bearing a supply of weft thread or weaving yarn, passes through the shed perpendicular to the warp, after which the depressed treadle is released and another treadle is pushed down, created a new shed. The shuttle then is passed in the opposite direction and the weaving process has begun.
Loom instructions and weaving patterns, or drafts, are essentially guides to inserting different colored weft threads in the warp and repeating. In a weaving pattern, colors are identified via a key using symbols or numbers, a circle for red, a diamond for blue, for example. In the art of fine Navajo weaving, the placement of weft threads is done by hand with manually applied battens and shuttles; the weaving projects done on floor looms depend on warping heddles according to pattern instructions and then following a sequence of treadling to create appropriate sheds necessary for a particular pattern. The combination of setting unique warping, known as sleying, and carefully following a treadling sequence to create sheds for a particular color weft thread will result in a predictable pattern emerging.
Once you develop a basic understanding of the loom instructions and weaving process and learn the names of loom parts and functions, following weaving and loom instructions should be easier. Guidance for setting up, or warping, your loom in accordance with pattern instructions as well as annotated glossaries of weaving terms and illustrations of patterns may be found in books and online. Most beginners’ guides suggest starting with simple patterns for weaving projects and, if more complex patterns are desired, weaving classes should be considered.