Friday, 4 September 2009

And notes for self

Projects in the queue:

  • Now that the weather's turning cold and you're finishing these scarves, dye that wool and start weaving the blanket for the bed.
  • Make a trial tote bag to test technique before committing handspun from spinning challenge (big enough to be a shower bag for work!) (ran out of time for this one)
  • Make tote bag from spinning challenge handspun....before the deadline
  • Make chenille-and-cotton handtowel to match the rest of your bathroom

THEN can you go on with all the projects your brain is trying to make you do!!!

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.

A jumble of pleats, part 1

With four of the five pleated scarves woven and my taking a break before weaving the fifth, it seemed a good time to blog the results of the experiments I've done on this warp. You can see from the image above, I've achieved some very different effects from the brown-and-beige striped warp I've had on the loom lately!

Because the pleats are designed to bend with the changing colours of the stripes, one side will appear all black with the beige in the bend of the pleat, and the other side will appear predominatly beige as the pleat beings the beige to the front and draws the black into the pleat. You can see both sides of the scarf in the image below.
The first scarf woven was straight 3/1, 1/3 pleats as I'd woven on the other warps. The ends were woven with a soft beige-grey 60/2 silk weft, and the main body of the scarf with a black 70/2 silk weft. You can see the margin of the two wefts in the image above.

When you stretch the pleats out, the effect is quite lovely.

The second scard was woven much the same as the first, but with a pale grey 60/2 silk weft and a reversing of the treadles. Instead of a constant repeat of 1-2-3-4 treadles, I'd treadle 1-2-3-4 six times, then treadle 4-3-2-1 six times. The effect was a lovely reversing twill pattern on both sides, but no difference to the structure of the pleats themselves, aside from a slight tendency to waviness that may have more to do with where they folded over the clothesline while drying.

Conclusion (a fairly obvious one): reversing the twill, while giving lovely patterns to look at in the fabric structure within the pleats, doesn't intrinsically alter the 3/1, 1/3 structure of the pleats, so won't alter the overall collapse pattern of the fabric.

But the patterns are, nonetheless, lovely, and open the way for ideas of pleated fabrics that are composed of a more complex twill structure. Something to think about and explore another day.

The obvious next step was to retie the loom and look at reversing the pleats themselves. More on that in the next post.

Tuesday, 1 September 2009

Clasped weft and colour design

This clasped weft is for a scarf I've been commissioned to do. The person who's asked for this liked the subtle interplay of blues and greens in another scarf I'd made, and I decided to take the concept one step further. I wound a warp rayon flake, graduating from navy blue through marine blue, sage green, grass green, light leaf green to yellow, with a small flash of golded thread at the yellow end of the spectrum. To mix things up a bit, there's an interleaving of the colours at the blue ends of the spectrum but not at the green-yellow end of the spectrum. For the weft, I dyed and spun silk cap in a cornflower blue and a variegation of soft blues and greens with a touch of yellow, in similar colours and hues to the warp. The variegation goes on the darker side of the scarf, the solid blue on the yellow wide of the scarf. I spin the silk cap very finely, as clasped weft results in a doubled weft.

I won't go into details of how to do clasped weft because Kaz Madigan at Curious Weaver does it much better than I could here. Logistically, I get around the concept of having a weft coming from either side of the loom by having one of the wefts still on a spinning wheel bobbin, and sit the lazy kate on the stash shelf beside the loom. Because the silk thread is so fine, it becomes very important to remember not to walk around that side of the loom! The structure is simply plain weave, so I depress a treadle, pass the shuttle from the right to the left of the shed, pass the shuttle under and back over the secondary silk thread (thus capturing the thread), and use the blue weft to draw both (now linked) wefts back into the shed. Then I can simply chose where to put the intersection of the two colours. This is where the fun comes in.

I try to let the varigations dictate where the intersection will be, but also work to keep the movement of the clasping looking random (a much less random act than you might imagine). Because I work in geology, this means that as I'm doing this, I think in terms of glacial or sea level advance and retreat - or in the case of this scarf, waves on a mossy shoreline. Nature rarely has straight lines. The edge is always wavy with little fingers of water moving forwards and some sections receding faster than others, and this effect looks more natural than a straight line.

With colours so similar in colour and value to parts of the warp, you can really have fun with the effects you make. Running green parts of the weft into the green section of the warp as in the image above can decrease the contrast between warp and weft and create areas of greater subtlety between warp and weft, but increase the contrast between the two wefts.

A different effect again can be achieved be creating a greater contrast in the darker areas of the warp: in this case, taking the yellow green right across to the left of the scarf, and allowing a contrast of yellow-and-navy with the cornflower blue of the left-hand weft:

I've taken these photos very close-up and from directly above to increase the contrast and make the effect as obvious as I can. From a distance and at an angle, the overall effect is much more subtle, and changes with changing angle. Running a part of the weft right across a similar colour can mean that the pattern fades in and out of focus in a very interesting manner, as you can see with both green and blue sections in the image below.

In addition to playing with the colours, the slight slubbiness of the woven silk cap gives this scarf quite a bit more texture than normal plain weave. This scarf is a great deal of fun to weave. I'm really looking forward to getting it off the loom to see how it looks as a whole but I'll miss the colours when it's done!