Designing Your Own Projects
New weavers sometimes fall into the trap of thinking they can only weave a project that they saw in a magazine, or online, or had someone tell them how to do.
Don't get me wrong, I love projects. Sometimes I see something so gorgeous that I just want to weave one for myself, without changing a thing. Or I'm just in a mood to travel in someone else's footsteps and let them do all the sampling and calculations.
But if that's all you ever do, you're missing out on an exciting side of weaving: the thrill of exploration.
Fortunately, designing a weaving project is a straight–forward process.
What to Weave?
The first step of any design process is deciding what to make. The goal of the textile (tea-towel, lingerie fabric, upholstery fabric, wall hanging, sculpture) will influence every design choice that follows.
In addition to figuring out the type of fabric you want to create, at this stage you should also figure out the size you want the finished project to be.
For example, you might choose to weave a soft, drapeable, woolen shawl with finished dimensions of 22 inches wide and 72 inches long.
The textile you chose in the first step will dictate the yarn you use. The characteristics of the yarn will affect the finished fabric, like the proverbial silk purse and sow's ear.
In the example above, a fine merino wool would be a good choice. The thin yarn would create a drapeable fabric and the softness of merino would keep it from being itchy when worn next to the skin.
You would not, for example, choose a bulky rug wool. Rug wool is made of coarse wool to withstand the abrasion of being trodden on. Perfect for rugs, it would make an inflexible, heavy, itchy shawl.
Another consideration here is color. Will your textile be monochrome, striped, checked, painted?
For the purposes of our example, let's choose a solid-color 20/2 worsted-spun merino wool.
The structure with which you weave your textile has a big impact on the finished fabric. The way threads interlace and interact affects the fabric's drape, loft, and shrinkage. It may also change the way the fabric needs to be sett.
For example, twills, because of their floats, need to be sett more densely to create a stable cloth, than the same yarn woven in plain weave .
When planning a project you should understand how the structure will affect the fabric. For example, if you chose to weave your woolen shawl in waffle weave, without understanding that waffle weave can have draw-in of 30%; you might be disappointed to discover that your finished shawl was only 15 inches wide!
The best way to learn about a structure is to play with it. Weave samples without any goal other than learning how the structure works. If you weave samples in the yarn you intend to use for your project, you will also get information about the weaving's draw-in and shrinkage after washing.
For the purposes of our example, let us say that we decided to weave our shawl in plain weave.
The sett, or number of ends per inch in the warp spacing, determines the density of the finished fabric. Sett too loose and the fabric will be sleazy, with a tendency for the threads to slide out of position. Sett too dense, and the fabric becomes heavy and inflexible.
You can estimate the sett for plain weave by wrapping the yarn around a ruler, counting the number of wraps in an inch, and dividing this value in half.
Other good resources for estimating sett are charts in the back of books such as Deborah Chandler's Learning to Weave and online resources such as sett charts compiled by weaving guilds like the New York Guild of Handweavers (Google "sett chart".) In addition, online weaving retailers often list sett recommendations in a yarn's product description.
These sett charts should be used as a starting estimate. The only way to be sure what sett to use is to sample. A fun way to try out several alternate setts is to weave a sample, cut it off the loom, and re-sley to a new sett to weave another sample. In this manner you can try out several setts and only warp the loom once.
Note: Some projects, like felting, differential shrinkage, crammed and spaced, and upholstery fabric, use setts outside the "normal" range. This is why sampling is so fun; you can discover intriguing fabrics when you "push the envelope."
For the purposes of our example, let's choose a sett of 24.
Calculating the Warp
After you know your finished dimensions, your shrinkage, your loom waste, and your sett, you are ready to calculate the warp you need to wind.
Note: Loom waste is the amount of warp that you cannot weave, in other words, the thrums left over from tying on to the front and back of the loom. It is different for each loom and can be affected by the method you use for warping.
For example, measuring the thrums at the beginning and end of my project, I get a loom waste of 18 inches on my Schacht Baby Wolf. This in the result of the size of the loom and the fact that I (warping back to front) use the end loops of the warp instead of tying on to the back, and use the efficient shoe-string lacing on method in front. On my rigid-heddle loom, using the same warping techniques, I might have loom waste of only 8 inches
Allowing for Shrinkage: The first step is to figure out the size you need to weave so that, after draw–in and shrinkage, your textile will be the correct size. The equation for this is as follows:
(finished dimension) * (1+(shrinkage as a decimal)) = (dimension to weave)
So if you wanted to weave a shawl 22 inches wide, and you knew that your 20/2 wool shrinks 10% (0.1 as a decimal) when woven at a sett of 24 epi (because of the sampling you've done) you would calculate the following:
(22 inches) * (1 + 0.1) = 24.2 inches
Thus 24.2 inches is the width you would need to warp for to have the finished fabric end up 22 inches wide.
The same equation works for the length as well. Say that our sampling had shown a 7% shrinkage in length, and we wanted a finished length of 72 inches:
(72 inches) * (1 + 0.07) = 77 inches
You would need to weave 77 inches on the loom to end up with a textile 72 inches long.
Figuring out How Long a Warp to Wind: Most warping boards are calibrated in yards. You can play around with different peg configurations to get a more precise length, but I find that so fiddly that I often just round up to the nearest yard. Any additional warp can be used for auditioning different wefts or to create sample swatches for my weaving records.
To figure out the minimum length you need to wind, add the length you will weave (before shrinkage) that you calculated above to your loom waste:
(length to weave) + (loom waste) = (minimum warp length)
For our shawl example, these figures would be:
(77 inches) + (18 inches) = 95 inches
Dividing this value by 36 (the number of inches in a yard) we get the minimum length in yards:
(95 inches) / (36 inches/yard) = 2.6 yards
Rounding up, we decide to wind a shawl warp 3 yards long.
Note: If your project will have fringe, remember to add twice the length of the fringe (assuming that both ends of the warp will be fringed) to the minimum warp length. The same goes for the length needed to turn a hem.
Calculating the Amount of Warp Yarn: Now that we have the sett, length, and width of our warp, we are ready to calculate the total amount of warp yarn needed for the project. The equation is as follows:
(width in reed) * sett * (warp length) = (total amount of warp)
Breaking this down, you can see how this works. The first two numbers, when multiplied together, give you the number of threads in the warp.
(width in reed) * sett = (number of warp ends)
The number of threads times the length of each thread, gives you the total amount of warp yarn required for the project.
(number of warp ends) * (warp length) = (total amount of warp)
Getting back to our shawl example:
(24.2 inches) * (24 warp ends/inch) = 580.8 warp ends
Since it's hard to wind .8 of a thread, I'm going to round up to 581.
Note: If you are winding a warp with a stripe or structural repeat every so many threads, you may have to play around with the warp width verses the weave patterning to avoid having partial repeats in your fabric.
So using 581 as the number of ends, I calculate the total amount of warp needed for my warp:
(581 ends) * (3 yards) = 1743 yards of warp required
Calculating the Weft
Calculating the weft works in much the same way as the warp calculation. Instead of sett, you use the ppi (picks of weft per inch of woven fabric.) Sampling will give you the exact ppi, or you can approximate (in the case of balanced weave structures) ppi using the sett figure.
The equation is as follows:
(woven length) * ppi * (width in reed) = (total amount of weft)
Like in the warp calculations, the woven length times ppi gives you the number of weft shots.
(woven length) * ppi = (number of weft shots)
Once you know how many weft shots there will be in the fabric, you simply multiply by the length to be woven to get the total amount of weft needed.
(number of weft shots) * (width in reed) = (total amount of weft)
Plugging in the numbers from our shawl example (since we are weaving a balanced plain weave, we will approximate the ppi by using the sett figure.)
(77 inches) * (24 weft picks/inch) = 1848 weft picks
Multiple the number of weft picks by the width in the reed:
(1848 weft picks) * (24.2 inches) = 44722 inches of weft
Convert inches to yards by dividing by 36:
(44722 inches of weft) * (1 yard/36 inches) = 1242 yards of weft required.
You'll notice that you typically need less weft than warp. That's because some of our warp ends up as loom waste.
Note: If math makes your head spin, you can use weaving software to calculate the warp and weft requirements for you (as well as other helpful things like how many heddles you need on each shaft.) Even when using software, however, it's useful to understand how the amounts are calculated.
Weaving without sampling is like driving without a street map. You'll get somewhere, but it may not be where you intended to go.
Sampling gives you the information you need to make accurate warp and weft calculations, it teaches you how the yarn and weave structure will interact, it gives you a place to test out different wefts and play with color, and most of all, if approached in a spirit of scientific discovery, sampling can be fun!
There are two situations where you can skip sampling and probably get away with it:
- When weaving something exactly like something you've woven before. (You don't need a street map to drive to your corner grocery store.)
- When working from someone else's pattern or directions. (This is like stopping at the gas station to ask for directions…and leaves you just as vulnerable to bad advice.)
I like sampling, but only because of thrill of exploration. Having to sample the same thing more than once would bore me. So I keep records every time I weave (drawing my own personal street map.) Keeping good records makes the most of your yarn and time spent in sampling.
It's a way to learn from your weaving, both your triumphs and disasters. Often you learn more from the disasters, and sometimes they pave the way to innovation.
I keep a notebook beside my loom at all times, constantly jotting notes about what I'm doing, changes to my orginal plan, and ideas for future exploration. The manner in which you keep records does not need to be elaborate, but it is important to get it down before crucial details are forgotten.
The best thing about your sample book? It's a weaving course tailored to your particular likes and interests.
All this calculation and sampling might seem like a lot of effort, but the reward is the freedom to design any textile you can imagine. The payoff comes when you take something from the loom that is wholly yours. Something unique and special.
And really, isn't that what handweaving is all about?
Syne Mitchell confesses that sometimes her love of sampling and exploration has turned entire warps into tiny, well-documented, scraps of cloth. Despite pleas from family and friends, she remains unrepentant. Occasionally, she pauses her sample explorations to blog at WeaveGeek.