What's a Drawloom?
It took me until I sat down and wove on one to really understand what a drawloom is, and how it works. The big picture is that it is a device that you add to a loom that allows you to pick up sets of warp ends in a pattern that then translates to a pattern in the woven cloth. Then you get down to the details.
There are two major types of drawloom devices. The first is the shaft drawloom, which combines the pick up threads onto shafts that are raised by the weaver to make patterns. This can let you make cool repeating patterns much easier than the second type, the single unit drawloom. With this type of drawloom, the weaver controls each small group of pattern threads individually. This allows for fine detail and non-repeating patterns. You can also buy a "combination" drawloom that merges the two together, letting you weave individually or in set groups as the design requires.
The drawloom achieves its effect through the use of two harnesses (set of shafts) and long eyed heddles on the front shafts. The pattern rises on the shafts on the back harness, then the front harness shafts manipulate those threads AND all the rest of the ground cloth (any threads not raised by the pattern shafts), raising some, lowering others, to create a stable cloth.
I'll make a movie of it sometime, because it's really not as complicated as it sounds.
The tiger weaving was my first attempt as using a drawloom ... I did not completely realize how much I had bitten off! Luckily, weaving on a drawloom is fairly straightforward. You raise the pattern units, then you treadle one sequence (for example, for a six thread damask, I would treadle 1, 2, 3, 4, 5, 6), creating one row of pattern/background. Then, you change the pick up pattern with the drawloom and weave through your treadles again. And ... repeat.