To get a good shed with the doup setup, the ground and doup warps need to be tensioned separately. I used the method in the monograph by Hella Skowronski,
Doup Leno. In it she describes how to construct and place "jumpers", or tensioners, behind the harnesses.
With the loom threaded in blocks in a point twill arrangement, the warps make a pretty pattern going through the jumpers.
The jumpers are simply dowels, placed on top of the warp and attached with big rubber bands to the loom frame to hold them down. Here is a side view of the first set of jumpers I was using. These are just wooden apron rods or lease sticks.
The rubber bands allow them to move up and down as needed as the different sheds are raised, keeping enough tension on the warp to make a clean shed, and keeping them from slipping out to the side. I attached them to the rod where the treadles pivot near the back of the loom. The bands are actually lengths of surgical tubing.
Skowronski describes the process of setting up the jumpers for two sets
of leno harnesses, but I found the description a bit ambiguous. I tried
several interpretations of what I was reading, but I found that I had
the most success when I tensioned each harness separately. With the
doup harnesses raised through the whole process, I raised all but one of
the back or ground harnesses, leaving the one lowered, starting at the
back of the castle and moving forward.
With these jumpers in place, the shed forms cleanly. But I found that if I open the shed completely wide, some of the warps raise up off the shuttle race a bit.
It works better if the shed is not opened completely.
In weaving doup leno, the beating takes some getting used to: because of the jumpers, the warp although taut is not held fixed like when it's coming straight off the beam as in regular weaving. It's more like weaving against a warp that is entirely weighted across its width. It bounces, and there's really not much to beat against. So it's sort of easy and gentle, not strenuous, nice summer weaving.
