Treadling Undulating Twills

Marcy Petrini


When discussing Undulating Twill (12/21/15) and showing the drawdown for the Christmas fabric, I said that the treadling was also undulating. And in discussing Colors in Nature (11/30/15), I mentioned that the scarf was threaded in undulating twills. The scarf is still on the loom, delayed by a combination of the holidays but also of spending a lot of time weaving and unweaving. Why? Because the beat in an undulating twill treadling can be tricky.

Here is the drawdown for the fall colors scarf:

The warp colors rotate: rust cotton, gold cotton, light brown silk and sage green silk, sett at 20 picks per inch (ppi). The weft is a yellow silk which I have chosen because of its luminosity. Despite the colors moving across the fabric because of the rotation, the pattern shows.

Using a standard tie-up (1 & 2; 2 & 3; 3 & 4; 4 & 1), the treadling proceeds from single shots – 1, 2, 3, 4 – to a doubling in steps: 1, 1, 2, 3, 4, followed by 1, 1, 2, 2, 3, 4, etc. And then reversing to form the diamond in the undulating pointed twill.

Whenever there are single shots, the beat can be as usual, the different sheds separate each weft. But whenever there are double shots, the two wefts in the same shed want to snuggle together and change the picks per inch.

To counteract the problem I first beat harder (30 ppi), which resulted in a fabric too stiff for a scarf; unweave. Then I tried to beat so that the double-shot areas were closer to the warp sett of 20, but the single-shot areas were too lose; unweave. I finally found a compromise of an overall beat of approximately 18 ppi: the double shots are always going to be a bit denser than the single shots, but as long as the fabric is consistent and drapeable, the scarf will be wearable.

Of course I could have avoided the problem by using an extended pointed twill treadling, but I like the undulations that the combination of the doubling in threading and treadling produces.

The sett of 20 is appropriate for a twill with a combination of 8/2 and 5/2 cottons and silks, but if I were to do this again, I may consider a bit closer sett, 22 perhaps. As long as each project has a lesson, the time working on it is well spent.


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