Weaving on a jacquard loom brings almost inconceivable flexibility. A traditional jacquard loom has a lifting device, a ‘jacquard head’ which sits on top of the loom, making the loom rather tall. Do watch the V&A’s video showing a schematic of the lifting device in action. A jacquard system lifts individual warp threads in contrast to a dobby loom which has a mechanical lifting device lifting shafts or sets of shafts. National Museums Scotland also have good information on traditional jacquard handlooms.
In the studio I weave on a TC2 electric digital jacquard handloom, using a foot pedal to engage pistons, valves and a blower to create a vacuum which raises individual heddles. Yes, heddles! There are no shafts on this single thread controller jacquard loom. Each heddle is controlled individually. Put another way, you could think of every warp thread as having a shaft all to itself. Threading is sequential from the first thread to the last thread across the warp, no block threading at all. I design the weaving sequence in advance in Adobe Photoshop, making each design into a black and white bitmap file for the TC2 loom to interpret. We can weave plain weave, twill and fancy figured designs without rearranging any threading. I change the sheds by pressing a foot pedal treadle like a sewing machine pedal. Watch the studio TC2 digital jacquard loom at work.
Imagine a 16 shaft loom threaded with super thick warp yarn, sett at 4 ends to the inch (1 end to the cm). The fabric will be 4 inches (10cm) wide. The threads are all threaded in a straight line on adjacent shafts as in the draft above. We can weave plain weave, honeycomb, 2/2 twill and lots of other things, without rethreading at all. It is operating exactly like a jacquard loom with an exceedingly narrow warp makes quite a chunky fabric.
The weaver can weave plain weave pieces on rigid heddle, two shaft looms, 16 shaft looms, and indeed a jacquard loom. The distinguishing feature in jacquard weaving is the ability to create a variety of complex figured fabric all on the same set up. She is of course constrained, as all weavers are, by the grist, fibre, colour and sett of the warp yarns on the loom.
For a brief note on shaft weaving read my posts on treadle and dobby looms.