This question often causes a mild headache for new weavers or those weavers who don’t really understand how their loom works.
Basically there are 3 types of looms. Counter-balance looms are known as sinking shed looms. This means that when you step on a treadle, whatever is tied to it will move down and the other shafts will move up.
On a Jack style loom or rising shed loom, whatever you tie to a treadle moves up while the other shafts just stay down at the bottom. And then there is the counter-marche loom that has two sets of lamms and you have to tie up both parts of the warp….you have to tell the loom what you want to go up and what you want to go down.
On a counter-marche loom, just remember that your lower lamms are your risers…they act like a Jack loom and your upper lamms are your sinkers, they act like a sinking shed loom.
This sounds complicated but it really isn’t.
Let’s look at a few tie-ups where all of this really matters. Warp predominant and weft predominant twills on 4 harnesses are a good place to start.
On a Jack loom a 1/3 tie-up, where you just tie-up 1,2,3,4 will be weft predominant fabric because you are only raising 1 shaft. That leaves 3 shafts down and you will be covering 3 warp threads with your weft…so you see more weft. If you do that on a counter-balance loom it will be the reverse, it will be warp-faced because only 1 shaft will be going down leaving 3 up and you will be going under those.
On a Jack Loom a 3/1 tie-up where you raise 123,234,341,412 will be warp predominant because you are lifting up 3 and your weft will be going under them, therefore you see more warp threads and the exact opposite will happen on a counter-balance or sinking shed loom.
It is so good to be able to think this through. Everyone has different looms.
When you are weaving a balanced twill called a 2/2 twill where you have 12,23,34,14 as your tie-up it really doesn’t matter how you tie it up….you will get exactly the same thing and you usually can’t see much of a difference between the 2 sides.
Where the difference really matters is when you are weaving more complex structures like overshot, or crackle or summer and winter, even laces, in structures where one side of the cloth will look completely different than the other side. This is when it is very helpful to know what type of loom the pattern was written for and to understand what type of loom you have. If you have a Counter-balance loom and the pattern was written for a Jack loom all you have to do is reverse your tie-up. All your empty tie-boxes become full with numbers and all your full tie-up boxes become empty. Just for your information patterns published by Interweave Press have tie-ups for Jack Looms. Patterns in older books like A Handweaver’s Pattern Book, by Marguerite P. Davison (also referred to as the green book)…those patterns are written for sinking shed looms.
Another thing to look for are o’s in the tie-up box or x’s in the tie-up box. Generally o’s refer to rising shed looms….think balloons, they go up. x’s refer to sinking shed loom…..think anchors, they go down 🙂
So if you find yourself weaving a more complex fabric and you are just following a pattern but what you are weaving doesn’t look anything like the picture in the book, just bend over and look at the backside of the cloth…the pattern you are expecting is most likely there waiting for you….and you are left with 2 options….just keep going and then turn your fabric over when it comes off the loom. Or if referring to the image in the pattern is helpful to you in regards to your confidence on the journey…you can reverse your tie-up under the loom and start over again. Whichever works best for you.
We generally write our patterns for sinking shed looms. If it is really important I will state in the pattern just so everyone knows. If I don’t write it in a pattern it is because it really doesn’t matter.
And if you are still having problems visualizing this, try doing a little drawdown. That has always helped me visualize what is happening at the loom. We went over how to do a drawdown in S4E1.
I do my drawdowns for sinking shed simply because it is the easiest way to do a drawdown…keeping that in mind make your decision about what tie-up you need to use is based on the type of loom you have. Or you could do a drawdown using Fibreworks which you learned about in S4E2, keeping in mind that Fibreworks tie-up default is set for rising shed 🙂