So, I've been experimenting using 2 rigid heddles. 2/1 twill is 1.5 times more dense than plain weave. So, in direct warping the heddles you need to pull half again as many threads through the slots as you would for 1/1 tabby. Even though you will weave with two heddles, you direct warp with just the back heddle in the loom. Using the warp beam to tie on your warp, then pull one loop through the first slot in the heddle and wind it on the warping peg at the distance you have calculated. Then loop your yarn around the warp beam for the second loop and pull it AGAIN through the FIRST slot in the heddle, and place the loop over the warping peg. around the warping peg. You now have 2 loops (which wil become 4 ends) thorugh the first slot. The next slot in sequence will only need one loop. Continue this pattern to achieve the 1.5 density required for 2/1 twill. Here's a diagram:
Then wind the warp under tension, and thread it very carefully using the following pattern (keep your wits about you! Constant Vigilance!):
Then , ta da! You've got a three shaft loom set up.
shaft 1: back heddle up, front heddle neutral
shaft 2: front heddle up, back heddle neutral
shaft 3: both heddles down
The sheds are very generous with this set up. It's so much fun to weave 2/1 twill this way!
note about selvages: once every 4th pick or so you'll find that just slipping the shuttle through the shed will skip the outermost selvage thread. When you notice it's about to happen, just slip the shuttle underneath that first thread on it's way through the shed. Then having caught the outer thread, everything will be fine and smooth. No gaps!
So, here are some samples:
1. woven by changing the direction of the shaft at 2.5 cm intevals (1,2,3,1,2,3...1,2,3,2,1,3...2,1,3). 2. playing around with weft stripes. 3. 1,2,3 weaving with dark weft and light weft.
Here's what my fine wool 2/1 twill looks like. I've folded it over to show the back.
Specs for the red and brown fabric:
100% wool (Finland) 2-ply fingering weight, 320 m/100g
48cm threaded in heddle, approx. 285 ends, 1.9 m long warp
required approx. 175 g brown wool for warp.
progress: approx. 40 cm completed
draw in: 5%
Pasanen, Mervi, "Aarreaitta: Tarton keskiaikaiset tekstiilit / what a treasure: Medieval textiles from Tartu, Estonia," in: Hibernaatiopesake (blog), 2015.
Rammo, Riina, Textiles Finds from Medieval Cesspits in Tartu: Technology, Trade and Consumption, (Thesis) Tartu Uliooli Kirjastus, 2015.