Friday 4 September 2009

A jumble of pleats, part 2

(Do forgive the draping over the ironing board, it was easy!)
The image above shows the four scarves currently off the loom. The left-hand one is the 'plain' pleated scarf, and the very right-hand one is the reversed-treadle pleated scarf. Of the two scarves in the middle, the left-hand one is the third scarf, and the right-hand one the fourth. These have both been made by reversing the treadling for the pleats.

The tie-up and treadling for pleats is a simple four-shaft straight draw, but with a twist. In the case of these scarves, the black can be considered block A and the beige block B. Block A are threaded 1-2-3-4 on shafts 1-4, and block B are threaded 5-6-7-8 on shafts 5-8. For these scarves each stripe was eight threads wide so I'd do one repeat of the threading, as in the draft below.

In this fabric, the treadling is straight and the structure is controlled entirely by the different threadings between the blocks, so the pleats occur between different sections of warp. Block A, on shafts 1-4, becomes a weft-dominant fabric and block B, on shafts 5-8, becomes a warp-dominant fabric. Obviously the reverse will be the case on the other side of the fabric. It's the natural inclination of the fabric to bulge into the weft-dominant parts that creates the pleats. presuming you have suitable yarns (ideally, the weft should be about half the grist of the warp), and you have a suitable (twillish) sett, it's not necessary to use overtwisted yarns in the weft to achieve this effect. These scarves prove that, as they've woven using rayon flake and the most passive reeled silk thread you're ever seen.

If you want to take that a step further, surely that would be to change the way the pleats work along the length of the fabric as well? So, with 8 treadles, the following draft allows that:

In this case, part of the fabric is treadled as before and part of the fabric is treadled on treadles 1-8, treadled as threaded. It becomes very easy to see which parts of the fabric are warp-dominant and which are weft-dominant, and how that changes along the block (is this starting to look like block theory yet Meg?). Black areas in this draft are weft-dominant, and white areas are war-dominant.

Of course, you don't have to echo the repeats. You can choose to make them as long and/or as short as you wish, which is what I did with the next two scarves. For the third scarf, I did an even 20 repeats of the treadles for each block. The end result was a striped effect, which gavea very pleasing twist where the interchange between the blocks occurred.

The weft, in this case, was an alternating three-shuttle arrangement of peach, beige and pale grey, which gave a very soft and complex colour. You can see the striped effect this has given the scarf in the top image.

But what happens if the blocks are an even size? Just how small do the blocks have to be before you stop getting the pleated effect? That's what I wanted to find out with the fourth scarf:

In this case, because weft is finer than the warp and so the ppi is smaller than the wpi, I treadled a steady six repeats of each block before changing on to the next. The weft in this case was a slightly thicker and rougher (compared to the 60/2 silk) handspun silk cap, dyed black - probably about a 30/1, 20/1. The amswer to the above questions was that you have to have blocks that are definitely longer than wide, in order to develope defined pleating in a fabric. But what you get instead...

Is the most delightful movement in the scarf. There's a definite bobbling between the blocks, as (on this side of the scarf) the mostly-beige blocks try to spring forward and the mostly-black blocks try to move back. In addition, the scarf does still try to crinkle into more-or-less vertical pleats as it's worn, giving a lovely drape and feel to it. And although it looks like a checked scarf, remember the weft is a single colour. The relative colours have all been achieved using weave structure, which really sets the mind to thinking about what could be done with exploring this structure with a number of colours of similar value. This may well be my favourite of the scarves so far.

There's still enough warp on the scarf for one more scarf in this series, once I've finished the blue-and-green clasped-weft scarf. The last one, to complete the series, will be woven with long stretches of one pleat, broken by short stretches of the alternate pleat, to see what that brings up.

3 comments:

  1. This is extremely interresting, thank you so much for posting this! I really enjoy to follow your very creative blog.

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  2. Yum yum. Each piece must be so lovely and exquisite, but seeing them altogether must be absolutely satisfying! I'd be queasy like a teenager if I had those in my room!

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  3. I love pleats, and love the photos of your work. It's very interesting to read about the design and how it works out.

    I haven't yet used silk in weaving, I'm just learning about linen which is very different to cotton or wool. I learning that the particular qualities of the different yarns means the same weave structure works differently. Do you think silk has characteristics that mean it works well in pleats? That is apart from the beautiful sheen of the finished scarf.

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