Flowing Curves: Overshot and Weaving as Overshot
Cloth is woven on a grid of vertical warps and horizontal wefts. But, with a bit of knowledge about designing weaving drafts, you can use these rectilinear elements to create smoothly flowing lines in your woven fabric.
I recommend that you start by designing curves in drafts, either on graph paper or in weaving software.
Once you understand how curves are formed, you can improvise curving designs at the loom; it's like freehand drawing with yarn.
In this article, I focus on designing with overshot blocks in order to create flowing curves large enough to be seen at a distance. I will also discuss "weaving as overshot" which is a method of applying overshot techniques to other weave structures and, finally, finish up with some strategies for designing curves in any weave structure.
Designing with Diagonals
The easiest place to begin is a study of drafts that use diagonal lines. When creating curves, the diagonal line becomes your drawing tool.
Any weave structure with at least three blocks can produce diagonals. All you need is a diagonal progression in the threading with a corresponding diagonal progression in the tie-up and treadling. The simplest diagonal draft possible is a three-shaft twill.
In the twill draft above, the diagonal lines are only three threads apart, which might be too subtle an effect. To make the scale of your design larger, you can use a diagonal progression of weave-structure blocks instead of individual threads. The following draft shows an example of a diagonal progression using overshot blocks on four shafts.
Overshot
Overshot is a weave structure creating a plain-weave cloth with decorative supplementary weft floats. These floats lie on top of (float over) the ground cloth. If you pull out all of the pattern weft threads, you are left with a plain weave cloth formed by the warp and the tabby weft. There are never any warp floats because of the tabby weft.
In the draft below, the first two treadles weave the ground cloth (tabby a and b) and the other treadles weave the four pattern blocks.
The tabby weft interlaces with the warp to form the plain weave background, so the tabby weft should be of similar value to blend visually with the warp. It does not have to be the same color as the warp. The tabby weft may the the same size as the warp, but I prefer to use a finer yarn for my tabby weft and a thicker yarn for my pattern weft.
As an example, if my warp is 8/2 cotton sett at 20 epi (recommended for plain weave) in white, my tabby weft will be 10/2 cotton, or perhaps 12/2. If my tabby weft is light blue, then the plain weave cloth will have a white warp and pale blue weft. I can change the color of the background by changing the color of the tabby weft.
The supplementary weft creates the pattern and is known as the pattern weft. Usually this is a thicker yarn than the tabby weft and it needs some contrast to show against the background. In the example above, an 8/2 or 6/2 or even a 5/2 cotton, or a similar size of wool, would be good for the pattern weft. In these drafts, the warp is light and the pattern weft is dark. Less contrast creates a more subtle effect.
Weaving software is very helpful for testing hues and values for weft yarns to use with your warp. If you choose to weave overshot with a single shuttle, choose a contrasting value to the warp for a subtle design but faster weaving.
Another benefit of overshot is that you can weave as many blocks (or areas of design) as you have shafts on your loom.
For more information about overshot, check out the following online resources:
- Block Design - Overshot, an overview by Rosalie Neilson.
- Weaving Overshot, an informative post from the How the West was Spun blog.
- Overshot, an online tutorial by Judie Eatough.
Now that we have selected a weave structure to work with, let's get back to designing curves.
Creating Curves
To create a curve from a diagonal line, vary the angle of the line's slope.
For example, you can transition a diagonal line into a steeper slope, a shallower slope, or gradually reverse its direction. Where the slope changes from one angle to another, you will see a curve in the fabric.
When you are creating curves, you have a choice - you can place the curve in the threading or in the treadling, or even in the tie-up.
What difference does it make?
If you put the curve in your threading, the waves travel across the fabric horizontally, in the direction of the weft. You can see this in the overshot draft below.
The benefit to having the curve in the threading is that the treadling then becomes a simple diagonal progression, which is especially useful if you are tromping the pattern, instead of using a dobby loom.
The downside is that handwoven textiles, such as scarves and shawls, tend to be longer than they are wide. Often a curve seems more natural when it flows up and down the fabric.
Another disadvantage to putting the curves in the threading is that it limits your ability to improvise curved designs organically at the loom. It's easy to change treadling patterns during weaving. Changing the threading, however, is a much more involved process.
So in this article, I will focus on vertical curves, designed in the treadling.
(Note: What happens when you place curves in both threading and treadling? Think about it. Circles and ovals!)
Changing the Slope of the Diagonal Line
I learned how to make curves by studying a traditional overshot draft called Blooming Leaf (page 133 in A Handweaver's Pattern Book by Marguerite Davison). In this draft, the treadling maintains a diagonal progression but the scale changes to make the shape "bloom" and undulate.
In order to make a curve, all you need to do is incrementally increase or decrease the number of times you repeat each pattern block in a diagonal progression.
To see how this works, use a diagonal threading sequence and start by treadling each block once, twice, then three and four times. You can see the diagonal line bend into a curve.
[Note: When I create overshot drafts, I place the first pattern block on treadle three; I like to weave the tabby picks with my left foot (alternating between treadles one and two) and use my right foot (on the remaining treadles) to weave the pattern weft and create the design.]
To make a line undulate, first gradually increase the number of pattern repeats for each block as illustrated below, then gradually decrease the number of times you repeat each pattern block in the treadling.
To make a curve turn back like a 'C' or an 'S', the diagonal line in the treadling sequence needs to reverse direction.
I start the curve by increasing the number of times a treadling block is repeated, going from the first pattern block to the last (and then wrapping around to the first block again to keep the line continuous). When the curve looks long enough, I reverse the order of the pattern blocks, going now from the last pattern block to the first.
Now that you know how to create curves, undulations, and reflected curves, you have the tools you need to create any kind of curve or diagonal line in four-shaft overshot. For a challenge, try making a long curve followed by a short curve, like a meandering river.
The methods described above also work for overshot on six, eight, ten, or more shafts. As you add additional shafts to your design, you gain the ability to create smoother and more dramatic curves.
Below is an example of an eight-shaft overshot threading; in this case a diagonal progression with a point and mirror symmetry. My treadling in this draft is an S-shaped curve. This is just one example of the many different curves you can weave on this threading.
Weaving as Overshot
Because the underlying structure of overshot is plain weave, any threading which can produce plain weave can theoretically be woven as overshot, alternating tabby and pattern weft.
Weaving as overshot implies the tie-up and treadling include certain characteristics of overshot drafts:
- The treadling includes repeated pattern blocks.
- The tabby weft blends visually with the warp, so that the pattern weft stands out. I generally use a tabby that is the same value (a measure of a color's lightness or darkness) as the warp.
- The pattern weft provides a visual or textural contrast with the ground cloth.
- The tie-up is usually a twill or a fancy-twill tie-up.
Curved treadlings look pleasing paired with a threading sequence which is diagonal and long, like an advancing twill or advancing points
In the draft above, the threading on the right shows a four-shaft advancing twill. The threading on the left is a series of advancing points (a short sequence followed by a longer one).
These examples show some of the options you have when designing curves - changing the threading changes the draw-down. The draft above uses the same tie-up and treadling as the reflected curve in the proceeding section, but you can see how using these new threadings creates smaller weft floats. Interestingly, these threadings have longer repeats than the first draft and smaller weft floats.
The next draft shows an example of an advancing-point threading on eight shafts. This one begins 1-2-3-4-5-6-5-4-3. The next point starts at 2-3-4-5-6-7.
I wove the draft above using a 20/2 silk sett at 30 epi. I chose to sett the yarn this densely so I could weave both an overshot and twill version on the same warp. You can see the resulting cloth in the picture below.
How do I weave as overshot when my sett is more appropriate for twill? I use a tabby weft that is much finer than the warp, in this case 140/2 silk from Lunatic Fringe.
Why weave as overshot on a twill threading?
- To get a different look and feel than twill cloth.
- For a clearer reading of the design, regardless of the number of shafts on the loom.
- To intensify the warp colors (by choosing a tabby weft that enhances the warp).
For example, the warp in the cloth below is hand-dyed in hot shades of red and orange. I chose a red tabby weft, so the background cloth would be very bright. For the pattern weft, I used a dark-purple yarn, with a deeper value than the background cloth. Because the pattern weft floats on top of the plain-weave ground cloth, it creates a textural, raised design element, which emphasizes the curved pattern.
Other times I choose to weave as overshot because the floats show off the pattern-weft yarn, such as the handspun wool used as the pattern weft in the cloth below.
It is easy and fun to make up a curved treadling at the loom, especially when weaving as overshot. Even after forty-two years of weaving, I still enjoy working with long, non-repeating treadlings; watching the curves grow and change as I weave. Instead of memorizing a sequence and repeating it carefully, I watch the design and think about where I want the next curve to go.
A side benefit of weaving long, undulating curves instead of small, repeated patterns is that a small variation in a repeat will stand out, but design variations are normal in organic curves.
So now that we've talked about all the reasons to weave your threading as overshot, what are the reasons not to weave as overshot?
- The drape of overshot fabric is not as fluid as that of a twill fabric. So for a scarf or shawl I might choose a structure other than overshot. Fine silk, however, has such nice drape that I can weave as overshot and still get good results.
- Weaving with two alternating shuttles (tabby and pattern) takes longer.
- Using two shuttles sometimes produces messier selvedges than a single-shuttle weave, because of the need to interlock the wefts at the edge of the fabric.
Regardless of which structure I choose; I like having choices!
Creating Curves in Other Weave Structures
Now that we've explored overshot, how do you create curves in other weave structures?
As before, it all starts with a diagonal line.
In order to create a diagonal line, you need at least three blocks of pattern. The number of shafts you need on your loom to weave three pattern blocks depends on the weave structure. Some structures, such as double weave, require several shafts per pattern block, whereas others, like summer and winter, are shaft thrifty.
In order to create curves, you must be able to lengthen an area to change the slope of the diagonal line while maintaining the weave structure. That’s it!
Generally this means repeating a treadling block. With a diagonal progression in the threading, you can treadle curves as long or short as you like. This applies to all weave structures.
With weaving software, it is easy to create curved overshot designs. Simply draw a freehand curve in the treadling—smoothing it out if necessary—and then add the tabby shots. Once you have the general idea from designing drafts, you can improvise new curved designs at the loom.
For other weave structures, creating a profile draft can be helpful. A profile draft is a design template that represents the woven design at one level of abstraction. To convert a profile draft into a weaving draft, you replace each block in a profile draft with the appropriate block of a given weave structure. You can, therefore, express a single profile draft in many different weave structures: overshot, summer-and-winter, Bronson lace, huck lace, double weave, etc.
Below is the weave draft created by expressing the profile draft above in the summer-and-winter weave structure, using a Dukagång treadling.
(Note: For more information about summer-and-winter treadlings, see Lillian Whipple's article, Summer and Winter to Taqueté.)
Profile drafts with smooth, flowing curves are also useful for learning how to design graceful lines. Weaving software helps because you can quickly create and edit drafts. None of the weaving programs I'm familiar with have an option to create "graceful" or "smooth" curves. So you'll have to train your hand and eye, but this comes with practice.
The weave structure you choose can subtly change the look of the curves you designed in the profile draft. After I use block substitution to express a profile draft into a specific weave structure, I often make changes to the draft to smooth out the curves or make them more graceful.
Another thing that can affect the smoothness of your curved designs is the number of blocks you have to work with. The more blocks you use in your design, the smoother your curves will look. A draft with only a few blocks is like a digital image with few pixels. It looks blocky.
The other factor affecting smoothness is the scale of the design. A miniature design can look smooth using only four or six blocks, but a larger-scale design—one using more (or larger) threads per repeat—needs more blocks or it will look pixelated. (Note: Sometimes the pixelated look is cool.)
I like smooth, flowing curves that are visible at a distance. So I look for structures that give me the maximum number of pattern blocks to design with. Generally I use weave structures where I have as many pattern blocks as there are shafts on my loom. On a four-shaft loom, I use crackle, overshot, advancing and network-drafted twills, advancing points, turned taqueté, rep, and shadow weave.
If your loom has more than four shafts there are even more choices. Network drafting is a method that greatly expands your options.
It is not always obvious how to make curves in a given weave structure. Sometimes figuring it out it takes determination!
The more you work with any given weave structure, however, the more control you have over it. Weave several different drafts in the same structure and it will become your friend.
Additional Design Tips
If you work with graph paper, remember to check the repeats, i.e., transitions, in the threading and treadling to make sure there aren't gaps or discontinuous areas that affect the flow of your curve. In weaving software, you can do this easily by zooming out the view to check the draft over several repeats.
To create a flowing curve with unrestricted movement, remember that the curve must wrap around from the last pattern block to the first, in the same way diagonal lines do, to create a continuous line.
Design inspiration for curves is everywhere: winding rivers, sand dunes, landscapes, roads, and so on. In nature, there are more curves than straight lines!
Bonnie Inouye has been weaving since 1967. Her award-winning work is characterized by flowing lines, intriguing textures, and bold images. She enjoys using weaving software to create innovative drafts for her sixteen- and twenty-four-shaft looms. Bonnie has taught in nine countries and authored many weaving articles as well as the book, Exploring Multishaft Design. You can hear her talk about her work on WeaveCast 28: Designing Multishaft Drafts. To learn more about Bonnie and view a gallery of her work, visit her website.
(Editor's Note: This article is part one of a two-part series. Look for Bonnie's second installment, describing how to create curves using network-drafted twills, in August!)