Carding is the process by which the individual wool fibers are individually straightened and sorted into separate fibers. Over a series of stages, this process converts a continuous matted web of fibres into individual ribbons of fine threads.
The machine (or, technically, series of machines in one long process) mechanically mimics the effect of hand-teasing and carding using spiked wooden paddles. This pulls the hairs into the same orientation to assist their spinning into thread, fluffing the wool as it develops. The process also helps remove any remaining dirt or plant matter, which would both weaken and coarsen the finished yarn.
The woolen mixture is carried through a series of rollers, each fitted with thousands of tiny spikes. In this way the fibers are caught and straightened as they are carried from one stage to the next.
A conveyor moves the wool first to ‘nippers’, which deliver a steady flow of the fibre onto the ’swift’. This transfer straightens the fibers, and the swift’s card cloth then carries these fibers past the worker/stripper rollers to the ‘fancy’. The worker roller turns more slowly relative to the swift, which reverses the fiber. The faster stripper then pulls fibers from the worker and passes them on again to the swift.
Over several stages, with the same process repeating from one machine to the next, this teasing and carding pulls the fibers increasingly parallel. And as it moves through, the wool becomes progressively fluffier and lighter.
Now that the base colours are fully mixed into the desired shade, and carded into the right consistency, the fiber is ready for to be spun into yarn. First it needs to be made into a loose thread.
The Roving machine picks up the fibers on ribbons, pulling just the right number through to make a very loosely organised thread. This thread has just enough strength to be wound ready for spinning. But it remains so loose that it can be easily pulled apart with the slightest tension.
For the yarn to have the strength required for weaving, it now needs to be spun into strong thread.The spinning is literally that – twisting it around 6-8 times, which gives the yarn a great deal more tensional strength.
The loose threads from the previous stage are wound onto a long bobbin. The yarn is gently pulled from here, down through a twister and onto the yarn cones below. At this stage it can still break easily, so the machine needs to be constantly tended.
Due to the loose thread’s fragility, the speed at which the spinner can operate is limited. But a large number of yarn cones can be wound in parallel at the same time so the highly skilled spinner is seldom idle.
The Warp is the long, lengthwise group of threads in weaving, through which the crosswise ‘Weft’ threads are interwoven to create its pattern. Because these threads are continuous, they must be organised in groups of the right sequence in advance.
The cones of Harris Tweed coloured yarns (each of which, remember, is formed from its own unique mix of base colours) are first arranged into the right layout, so that each thread comes off it in the right position for its own unique position in the pattern.
The threads are then arranged in groups on the warping frame, in lengths that might vary from just a few yards (metres) for a short weave – say, for a single garment – up to eighty yards or so for a full ‘piece’ (the standard unit of a full weaving length). The warping frame needs enough pegs for the longest warp to be strung between them without a break.
Once hundreds of warping threads have been laid out for the full width of the loom where it will be woven (which may be either ’single’ or ‘double’ width) they are wound up into hanks, and sent out to the weaver’s home, ready for the weaving itself.