Wednesday, 14 March 2007

New tabletweaving project - seal tag

Well, last weekend I started a new tabletweaving project. It's a copy of a 13th C seal tag, with different colours.

About the original piece
This tag is described (along with 4 others) in:
Henshall, Audrey. "Five Tablet-Woven Seal-Tags." Archaeological Journal 121 (1964), pp. 154-62.

I can't find the article online, nor anything about this pattern, but did find a reproduction of one of the other seal tags from the article.

The diagram to the right (Created using GTT) shows the pattern. On a white background, squares of salmon pink and dark blue with pale yellow-green centres. Spiral/tubular tabletweaving technique has been used -the weft passes only in one direction, stitching together the two sides into a tube (ie the back is never visible).

Technical details reported by Henshall:

  • on a charter granted by John de Balliol King of Scotland 1 August 1294
  • S twisted, Z plyed silk
  • White and green yarns thinner than others, green used double
  • White also used for weft
  • 1.5mm wide, 46cm long (remaining)
  • 16 threads per cm
  • All tablets except 4th tablet (all white) threaded in the same direction
  • reversal points every 1.75 to 2.75 inches
I'd like to post a picture here of the original, but the photocopy of a photocopy I've got is rather low resolution. (If anyone has access to the journal and a scanner ...)

Choices for my reproduction
So, I decided to dig out my silks. I chose the lochac colours of (off) white, red and blue, since I don't have any use for a seal tag, so it might as well enhance the glory of the Kingdom. With only 3 colours instead of the original 4, I decided to use background white inside the squares replaceing the green. Blue and white remain the same as original patern (including using white for the warp), and red replaces the pink.

The silks are 60/2 and I didn't check the spin direction, but I suspect the red and blue are conventional S spun, Z plied. The white is actually 90/3 I think, which is pretty much equivalent to 60/2, but there is something less satisfying about this roll of thread. It unplys easier and tangles more, and also snaps easier. I think this might have to do with the direction of the spin and plying, or just the extra threads. At any rate, I much prefer the colours for working with.

Other than the colours, I've attempted to make no other changes to the patterns on the original.

My observations

That picture is approximately real size (sorry it's so dark - no flash on supermacro mode). I've woven approx 20cm already in about 3 very distracted hours, so it's working up quite quickly despite the fineness of the thread.

The width of my band seems about right. It looks to my eye to be more than 1mm and less than 2mm. I need to check it against a ruler, but unless I'm wrong, I'm not going to get much more accurate than that without someone to lend me a micrometer.

I need to count the number of threads per cm, but i suspect it's less than 16.

Henshall says the cord spirals when the direction of the cards and twist of the yarn coincide. My cord spirals in both weaving directions, but it does seem to spiral more in one direction.

If you haven't worked it out from the last section, the off-white thread has been a pain. Used single as a weft it snaps frequently. (yes that is what the fluffy bits are in the picture) Using it doubled seems to fix that problem.

I can't get the tension as tight as I would like (even when the warp doesn't snap). The join between the sides is approx 3 cords (ie 4 threads that go through a tablet) wide and ladder like. This makes the cord unsymmetrical as one side has one cord between the squares and the other a much larger gap. I can't get enough detail on my photocopy to be sure, but I think the original is nearly symmetrical.

The one card threaded differently Henshall interprets as a mistake. I'm not convinced. The fact that it's the all-white card between the two squares makes this contentious. The designer could be trying to offset the spiralling a bit. But then that leads me to ask why both all white cards aren't alligned in the opposite direction. Until I wove it, and realised that the direction of the edge white card is obscured by the warp thread anyway. I think it is possible the direction of that card was deliberate, although the other all white card may have been intended to sit in the same direction also.

I wove a small section with all cards facing in the same direction. The white line appears sightly broader, but that's about the only difference.

My first reversal point was less frequent than in the original - approx 10-12cm rather than 1.75-2.75 inches (4.4 to 7cm), and My threads weren't very tightly twisted when I did remember to reverse. I can concieve of 3 reasons for a smaller distance betwen reversal points:
  • They worked at a much higher tension than me, and so the threads got too tight to turn easily more quickly than my threads.
  • They deliberately used reversal points before the tension significantly increased across the threads in order to achieve a more evenly tensioned product
  • They were working on a significantly smaller loom than me
The first option seems unlikely - my tension is a bit loose today, but not very much so.
I'm not sure I buy the second option - I know people who are using swivel hooks because they couldn't find a reversal point in 2m of all forward viking tabletweaving. The reguar irregular spacing speaks more of necessity than memory.

The last option interests me most. Most of the pictures and one extant loom we have are of band looms approx 2m across. My loom is only 1m across. And yet to get tight threads after such a short distance, I'm estimating a 50-70cm loom would be required. We don't have many pictures of small looms. And yet, just as big looms make sense for large projects, smaller looms for smaller projects would make tensioning during warping up easier.

I just don't have enough evidence to do more than speculate.