Introduction:
All but two illustrations are from my book, Weaving for Beginners. The 2-shaft drafts come from the book shown in a previous post, Adventures in Weaving on a 2-harness loom. NOTE: harness is a common word used for shafts. Shaft is the more correct word and is used here and in my books.
The book, Adventures in Weaving on a 2-harness loom” shows the threading for 2 shafts like in the illustration. (Shafts are often called harnesses.) The two rows represent the 2 shafts. Dots show every other thread on the bottom line and the alternate threads on the top line. And, to show a different color of threads for a stripe, the squares of the graph paper are filled in. In other words, for one color area, both shafts are that color and for another area, both shafts are threaded with another color. The first shaft is always indicated on the bottom line and shaft #2 is on the line above it in American books.
To change from 2 shafts to 4 shafts we often think of odd and even numbers. With a threading on 2 shafts, you could think of shafts 1 & 2 alternating as “odd, even, odd, even, etc. rather than 1,2,1,2,1,2. You would use that idea to switch to 4 shafts. The odd shafts are 1 & 3 and evens are 2 & 4. Then you would use the rows in the threading draft 1 & 3 instead of the bottom row (shaft #1) and 2 & 4 for shaft #2. In the illustration the sequence of 1,2,3,4 is shown for the threading. When weaving, you would raise shafts 1 & 3 for a row and 2 & 4 for the alternate rows. Then you would be getting the same plain weave (or “tabby”) as though you were weaving on only 2 shafts, alternating rows with shafts 1 & 2.
In weaving drafts for more than 2 shafts, the American convention is always to show shaft #1 on the bottom line and each additional shaft on the lines going upwards from the bottom. The illustration shows how the threading for 4 shafts would work. If there were 8 shafts, shaft #1 would still be on the bottom line, but there would be 7 more lines above that to indicate 8 shafts. The same principle would be for 12, 16, or 32 shafts, etc.
In my previous post on January 27, 2021, Log Cabin patterns were the subject. That particular pattern depends on threading alternate threads in light and dark. The illustration shows an example of a threading and some patterns on 2 shafts. In the illustration, dots represent light threads and solid squares, dark threads. Note that in the area on the left the lights (dots) are on shaft #1 with darks on #2. In the right area of the draft, it is the reverse with darks on shaft #1 and lights on shaft #2.
To change from 2 shafts to 4 shafts, think again of odds and evens. What was shaft #1 becomes #1 & # 3 –both odd numbers. What was on shaft #2 becomes #2 & #4 –even numbers. And notice carefully that in the illustration, the lights are on the odd shafts on the 4 threads at the ends of the draft and the darks are on the odd shafts for the center 8 threads.
The illustration shows that by switching the placing of the lights and darks, the pattern changes. Note too, that the WEFTS also alternate dark and light to create the patterns and the changes. This is typical log cabin. Often the blocks are all the same size, but they don’t have to be. The widths in the threading determine the widths of the blocks. The height of the blocks is determined by the number of rows woven in a light/dark sequence.
This illustration shows a different way to think of 2-shaft weaves. With 4 shafts you can think of 2 looms: 2 shafts (1 and 2) for one loom. And shafts 3 & 4 can be thought of another 2-shaft loom. That means you could have two different things going on at once. For example, log cabin on shafts 1 & 2 and what every you might like on 3 & 4 for example solid areas or stripes. We call the different “looms” block A and Block B. With more shafts and different patterns, you can have more blocks, say C and D.
Another illustration of 2 blocks. This would be a good idea when using thick and thin WEFTS like in my post on January 29, 2021. You decide what you want to show in Block A, (e.g., lights) and in Block B: lights as well, or darks. Because the blocks are on different shafts they can act independently. See the next illustration.
Thick and thin wefts are woven in this variation of rep weave. Notice that the 2 blocks can be alike (at the top) or different when weaving. The threading can never change, but which shafts you choose to have showing at any one time is up to the weaver. More information about this weave is in Weaving for Beginners. Here I just want to show how 4 shafts can be thought of as 2 looms with 2 shafts each.
Here’s a draft showing an example of the shaft numbers for a two-block design: a center field with borders on the edges.