Designing a Twill Gamp: Part 2

The threading plan

A classic twill gamp consists of areas (usually squares) of different twill interlacements. The warp is made up of sections threaded with different sequences, e.g. the straight draw, the point draw, and so on.

We’ve already talked about general issues of scale and the impact this can have on the design of your gamp. To get to a detailed threading plan, there are a few more decisions to be made.

Which twills do you want to include?

You may be eager to cram in as many as you can, or you may want to focus on just a few. As noted last time, if you have a small loom and a chunky yarn then you will probably need to take the focused approach! This can be a good thing as it forces you to be selective and choose the twills that will be most rewarding, depending on your interests. You might opt for three or four threadings that are quite distinct and different, and perhaps outside your ‘usual diet’; or you might prefer to work with subtle variations on a theme, such as different scales of point twill.

I have already recommended The Handweaver’s Pattern Book (Anne Dixon) and Designing Woven Fabrics (by Janet Phillips) but will heartily do so again. Either of these books provides a good resource for twill threadings, and Phillips’ book is especially rich in this area. The classic A Handweaver’s Pattern Book by Marguerite Porter Davison is also full of twill ideas, as is GH Oelsner’s A Handbook of Weaves.

Finding the repeat

To put together different threadings, you need to identify what constitutes one ‘repeat’ of each threading you want to include. In some sources the basic repeating unit* is clearly identified; in others you may need to do some close inspection to pick this out.

For instance, we often see a point draw written out like this:

point threading

which may lead us to think of the basic unit as a single triangular point:

seven end point

However, we cannot place units like this side by side, or we would have two consecutive ends on shaft 1. In fact this threading draft can be broken down into regular 6-end units of this uneven shape:

six end point

Placing these side by side will give us the repeating pattern of points:

point threading showing repeat

If this is your complete threading then you may choose to balance the design with one extra end on shaft 1 as shown above, but that is not necessary or even desirable for a gamp.

Building a composite threading

Why do I say that this balancing end is not desirable? Because we are going to fit several threadings together into a composite design and want the transition from one section to another to work as easily and smoothly as possible. We already have several constraints to think about, including making each section roughly equal in width while maintaining the integrity of the twill, and keeping each pattern to a regular repeating unit will assist us with that.

For example, suppose I want to have a section of point draw followed by a section of broken twill. I have identified the following two threading units:

six end point

broken twill

I can easily set them side by side, and the last end of the point draw (on shaft 2) is neatly followed by the first end of the broken twill (on shaft 1).

composite threading

Or, if I want to have a contrasting border between sections, I can just as easily slip four ends of a straight draw in between the two:

composite threading with border

You may spot that the straight draw just looks like a continuation of the point draw: effectively it is! In some cases the elision of one threading into another may be so smooth we barely notice it. The border here is marked only by the contrasting colour, while the same four threads placed between two other threadings may be more distinct. The main purpose is achieved as long as there is no awkward misalignment as we move from one section to another (scroll down to ‘What we are trying to avoid’ for a misaligned example).

Thinking in multiples

Given the way we are defining the basic unit of each pattern, most threadings suitable for four-shaft twills will be multiples of 4, 6 or 8 ends but some may be as long as 12 ends (or even longer). This is why I suggested in part 1 that you aim for 48 or more ends. 48 is an excellent number for our purposes as it is divisible by all of the above! 36 ends is not bad, but units of 8 ends – such as a vertical herringbone – won’t fit exactly.

In the example above, I have a tiny section of just 12 ends. This allows me to include 3 repeats of the broken twill threading or 2 repeats of the point threading. Suppose I wanted to include a vertical herringbone, and had identified this threading:

vertical herringbone

I have decided to place the vertical herringbone between the other two threadings so I have the following gap to fill:

threading with gap for new section

How might I achieve this?

Since the unit is 8 ends, I need one-and-a-half repeats to give me 12, so one option is this:

first attempt at adding herringbone to threading

It fits, and it gives me a neat beginning and end where it meets the straight threaded border. However, if I decided to double up the second half of the threading (the part that begins on shaft 2) rather than the first half, I would get this:

maximising herringbone effect

And the advantage of this option is that the clean break between the two halves of the herringbone is continued into the junction at the border, so that the visual effect will be much more ‘herringboney’ and give me real value-for-money in that section.

I can now complete my #tinygamp with a border on either side, and I will have this as my final threading:

complete tiny gamp threading

What we are trying to avoid

One of the slippery things about twills is that they are so versatile it can feel hard to pin down the essentials. Why do I say this…

herringbone

…is my herringbone threading, rather than this…

alternative herringbone

…for example?

The truth is that these are both perfectly good threadings for obtaining the same result in the cloth. But in composing a gamp, I want to make sure my threadings work seamlessly side by side, so I choose the variant that works. If I used the second option, and tried to place it into the gap I created above, I would get something like this:

misaligned herringbone

Can you see what has happened at the borders of the section?

misaligned herringbone highlighted

Here the threading reads 3-4-3-4 and 1-2-1-2, which disrupts the integrity of the twill. In practice we would get excessively long floats in these areas.

To sum up

The lesson, then, is to be flexible and a little bit devious when identifying your irreducible threading units! If you establish a common rule, such as ‘every threading will begin on shaft 1’, you will find it much easier to wriggle them into working well with each other.

This process is well worth tackling with pencil and squared paper, even if you don’t plan to weave a gamp in the near future. Setting different threadings side by side is useful in many applications – ever wanted to customise a border on your table mats, for instance? – and the considerations of working with multiples and getting a neat fit are always relevant.

 

* I use the word unit throughout this post to describe the minimum number of ends that describe a distinctive threading pattern. This is just because it is a really clear and handy word for this purpose, and is not to be confused with the technical terminology of ‘unit weaves’ which is another topic altogether!

First posted on weavingspace.co.uk © Cally Booker

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