Designing a Twill Gamp: Part 4

Weaving your gamp

One of the pleasures of weaving a twill gamp is that you get to make up this part as you go along! However, there are a few steps you can take to bring some order to the process, so that you don’t become overwhelmed by the possibilities.

The right approach for your loom

Table looms

As I have discussed previously, here in the UK many of us weave on table or dobby looms rather than treadle-style floor looms. Without, I hope, being too parochial about it, I must admit that I do think a table loom is the ideal loom for this kind of project. With one independent lever for each shaft, you can very easily create a shed in any of the possible combinations of shafts and there is no need to commit to a specific tie-up. And if you are in the early stages of your weaving life, seeing the levers right in front of you and manipulating them individually can really help to forge the three-way connection between the draft, the loom and your brain.

Floor looms

Having said that, if you are weaving a 4-shaft twill gamp on a jack loom then a direct tie-up will deliver many of the same benefits, if not quite as transparently. A direct tie-up is where you tie one shaft to one treadle, so depressing the treadle for shaft 1 will operate shaft 1 on its own. To lift more than one shaft, you need to depress all the relevant treadles. Here in Scotland, those who weave traditional tweeds on a floor loom often use a direct tie-up like this one…

universal tie-up

…which allows the weaver to treadle a 2/2 twill very efficiently by using both feet, as shown below. Plain weave is a little trickier as the weaver needs to place either the left or the right foot over two treadles together, but if your loom’s treadles are close together this is a neat trick to practice.

universal tie-up with treadling

If you have six treadles then an alternative for a 4-shaft tie-up is to use the outermost treadles to tie up the plain weave lifts 1 & 3 and 2 & 4.

universal tie-up on six treadles

Universal Tie-up

Both of the approaches above offer what is called a ‘universal tie-up’. This is a tie-up which will allow you to treadle any of the 14 combinations which create a shed on four shafts, so you are not limited to twills: you can use it for any weave structure. If you haven’t come across a tie-up like this before, then it is a good exercise to think through what those combinations are and how you would make them. For instance, how would you weave a 3/1 twill, where you are lifting three shafts at a time?*

Treadling as drawn in

The heart of your twill gamp is achieved by ‘treadling as drawn in’ each of the different threadings you have used. This means that you mimic the sequence of your threading with your liftplan or treadling and, in this context, you create a patchwork of designs, where every threading is ‘crossed’ with every treadling. Along one diagonal you will see the ‘as drawn in’ result for each individual pattern. It is an invaluable library of samples all in one lovely piece of weaving.

Schematic diagram of the squares in a twill gamp

But how do you treadle as drawn in, when you either have no treadles or your treadles are tied up in universal fashion?

The Twill Progression

Back in one of my first posts I described the idea of the twill progression. At its simplest, this is the sequence of four lifts which constitute one complete cycle of the balanced four-shaft twill. We can assign a number to each of these lifts – the numbering is essentially arbitrary, but it is commonly given as:

1: raise shafts 1 & 2
2: raise shafts 2 & 3
3: raise shafts 3 & 4
4: raise shafts 4 & 1

This scheme is particularly easy to work with as the number assigned to the lift corresponds to the first shaft in the lifted pair.

Putting it together

To treadle as drawn in, you simply read off the shafts in your threading sequence and substitute the matching-numbered lift. So if you threaded 4-3-2-1 in a straight draw, you would also weave the sequence 4-3-2-1 which in full would be:

4: raise shafts 4 & 1
3: raise shafts 3 & 4
2: raise shafts 2 & 3
1: raise shafts 1 & 2

If you are weaving on a table or dobby loom, this is your liftplan: you can take it straight to the loom and start weaving.

If you have a floor loom tied up as shown above, then you need another step to interpret this sequence as a pair of treadles. Which treadles raise 4 & 1? Which raise 3 & 4? And so on**. Given that there are two distinct steps to get from threading to liftplan and then from liftplan to treadling, this is a scenario which cries out for a pencil and squared paper! Keep a notebook by the side of your loom, and you will soon get into the habit of jotting down the lifts you need and reinforcing that brain-draft-loom connection.

Moving onto new combinations

By the time you have woven all your threadings as balanced twill treadlings, you should be in a thoroughly twillish state of mind and ready to improvise.

You can try varying what you’ve done by repeating the ‘treadling as drawn in’ exercise, but raising just one shaft per pick instead of two. So every time you have a ‘1’ in the threading sequence, you lift shaft 1; a ‘2’ means you lift shaft 2 and so on. That will give you a weft-faced twill on the face of the cloth and a warp-faced twill on the back.

Or you can include all the variant patterns you didn’t have room for in the threading.

Or you can start to mix up twill and plain weave lifts.

Or… You get the idea. You will surely run out of warp before you run out of options.

To Conclude

I hope this series of posts has given you some useful resources for designing your own twill gamp. It is impossible to write comprehensively on this topic as the options are limitless; but that is exactly what makes it a fun and rewarding project. If you have any questions that I haven’t already addressed, then please let me know and I will do my best to answer. And if you have had a go at this project, then I would love to hear how you got on.

*The easiest way is not to do it! Weave a 1/3 twill and turn the cloth over when you’re done. But if you want a pattern which includes stripes of 1/3 and 3/1 twill, then you’ll need both treadlings.

** The required sequence is actually the 2/2 twill I have shown above, if you read the treadling from bottom to top (i.e. the bottom row is the first pick and the top row the last pick).

First posted on © Cally Booker

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