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Twill Blocks Tie-Up |
Marcy Petrini
August, 2024
It invariably happens that when I teach a topic, I come away with more ideas. I offered a seminar on blocks at Convergence® 2024 and as I was finishing the handout, I thought of things that I wanted to change.
One of the areas is twill blocks on eight shafts. In my monograph on eight shaft twills, I have taken a straight draw and wove the two halves as 1/3 and 3/1 broken twills, forming blocks, one block weft dominant, the other warp dominant and then reversed. We also call these twills false satins, so two blocks of false satins form a false damask.
Below is the drawdown and the fabric woven from it.
There are two lessons to be learned from these figures. We can see that they are formed with broken twills; they are false satin and not true satin blocks because the twill lines are still visible. A true satin has “the suppression of the appearance of diagonals” as defined by Emory (Emory, Irene. The Primary Structure of Fabrics. Washington, D.C.: The Textile Museum, 1980.)
The second lesson is that floats of a 1/3 and 3/1 twill should be three threads long for both weft and warp floats. In the above fabric and drawdown, I wasn’t careful and where the blocks meet, some of the floats carry over into the next block, sometimes resulting in a four-thread float.
In some of the variations of this structure, Carol Strickler in her book (A Weaver’s Book of 8-Shaft Patterns) describes these blocks as having units, one on shafts 1 through 4 forming block A, the other on shafts 5 through 8 for block B. The same twill is used for both units and each unit can be repeated. The drawdown below is an example. Block A is formed with two repeats of the straight twill on four shafts; block B is the same configuration, but on the second set of shafts. The treadling is weaving the blocks to square, one weft dominant, the other warp dominant, and then reversing.
This drawdown also appears in my monograph, and it has the same problem as the previous one: floats continuing into the adjacent block.
Now, however, I want to weave this structure, so it’s time to think about making the floats the correct length. I could just copy the tie-up and treadling from Strickler’s book, but I want to understand how to manipulate the tie-up to achieve that goal. I have seen others just break the twill and not worry about the spill-over floats as I did. We can think about developing the correct tie up. (The next set of figures derive the drawdown; if you don’t want to follow it, see Figure 11, the final result.)
When I weave broken twills, I usually “break” the twill in the threading, between shafts 2 and 3. Thus, the resulting threading is 1, 3, 2, 4. When treadled as a 2/2 straight draw, this has the advantage of not needing floating selvages because of the odd vs. even edges in the threading.
However, straight twill threadings are more versatile for twill blocks. Then the tie-up can be broken. I used the same 1, 3, 2, 4 which resulted in the next drawdown.
This portion of the tie-up and treadling weaves blocks A weft dominant.
We can repeat this tie-up for the second block; however, the weft-dominant tie-up and treadling for block B must occur when block A weaves the warp-dominant twill, as in the drawdown below:
The next step is to find a warp dominant tie up for the shafts 5 through 8. There must be three warp thread and one weft thread for each twill repeat. Warp threads in the warp dominant block B cannot be adjacent to warp threads at the edge of the weft dominant block A. It’s a bit like solving a puzzle.
I approach this tie-up by figuring out which shaft can be tied to which treadle, using the limitations described above.
Shaft 5 can show warp with treadling step 1, 2 and 3, since the adjacent shaft 4 shows weft. Then treadling step 4 for shaft 5 will show weft, since shaft 4 shows warp. The drawdown is below:
We can use the same strategy on the other side of the block, with shaft 8. Shaft 1 shows warp with the first pick, and weft with picks two through four. Thus, shaft 8 must show weft on the first pick and warp for the remaining three, as shown in the drawdown below.
Next, I want to look at the bottom and the top of the warp-dominant block B where it meets the top and bottom of the weft-dominant block B. In order to see top and bottom I must extend the treadling steps 1 through 4.
For treadling step 4, shafts 6 and 7 must show warp since step 5 shows weft. For treadling step 1, shafts 6 and 7 must also show warp since step 8 shows weft.
Next, we need to fill in the treadling by following the rules: warp on shaft 6 for treadling step 3, in order to have a three-thread warp float. Similarly, warp on shaft 7 for treadling step 2.
Our last step is to do the tie-up for warp-dominant block A, which we do in parallel to block B. To complete the drawdown, we repeat treadling steps 5 through 8 again. Below is the final drawdown.
Done! To check that all the floats are never longer than three threads, I use the float analysis of the drawdown software and it confirms it.
Describing the process takes longer than to do the steps!
I figured that there is more than one way to treadle these twill blocks. I was curious what tie-up is used in Strickler’s book, so I did the drawdown exactly as it appears, shown below:
Totally different approach, same result.
While going through the process, I noticed how the tie-up is organized, which is more obvious when looking at it as filled boxes rather than numbers. On the left is the one we just derived, on the right the one from Strickler.
The parallel images of the opposite quadrants and the mirror images of the adjacent quadrants are obvious and can be used to determine a drawdown.
Next time you look at a complicated tie-up, and wonder how the weaver ever arrived at it, now you know!
And the fabric…. The warp is wound…. Stay tuned….
Happy Weaving!
Marcy
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Eclipse |
Marcy Petrini
July, 2024
I am fascinated by eclipses of the sun. I can imagine how frightening it must have been in ancient times when people didn’t know what was suddenly causing the covering of the sun during the daytime.
I remember as a child in Rome, Italy, an eclipse was occurring early in the morning. School postponed opening till the peak was over so that everyone could experience the eclipse at home. We lived in an apartment building with a rooftop terrace, and everyone gathered there to watch it. I also remember walking to school partly in the shade as the sun was slowly returning,
In 2017, the eclipse was going to be partial where we live in Jackson, MS, so we traveled to Kentucky for the August 21 totality. We were parked in a field provided by a distillery. For a small fee, and first come, first serve, we found the perfect spot, with lots of kindred spirits watching, cheering and clapping. We brought special glasses that allowed us to look at the eclipse as it evolved. We were lucky, an incredibly clear and blue sky – while the sun was uncovered. Terry had a filter for his camera; he took periodic pictures and then put them together for a short slide show (< 30 sec.). Here it is:
https://terrydwyer.net/images/video/adapting to the dusk of totality.mp4
Back at home, I was inspired to weave this scarf:
I chose M’s & O’s as the structure for my scarf, I don’t remember why; perhaps the O’s reminded me of the sun. I used 10/2 mercerized cotton in a gold color for the warp; the black weft was 20/2 silk, the bright yellow weft was a silk from my stash, close to an 8/2, but the two wefts worked well together despite the difference in size. I divided the 65” length of the scarf in 5” segments, starting with 5” of yellow, introducing ¼” of an inch for the following 5” segment, and then progressing by changing ½ an inch with each 5” segment, until the end, where the last yellow was ¼” and the scarf ended with 5” of block.
I really like the scarf; whenever I need an example of M’s & O’s, I use one of the segments, like the one below.
This year, we travelled to Arkansas for the April 8, 2024, eclipse. Terry chose Lyon College for our site; the college was very welcoming, providing all sorts of programs related to the eclipse, plus food, vendors, and a great spot for us to set up and watch with some faculty and staff. Once again, we were lucky because we had a clear sky. This one was nearly double the totality from the 2017 one, so we were able to take our glasses off and admire for several minutes the sun with its prominences, visible in the photograph that Terry’s took:
Time for a scarf to commemorate this eclipse. This time I decided to make the gradation in the warp. I used 20/2 silk for both the black and the gold with a set of 30 epi. I adjusted the width to 9”, so I could use 9 segments. I started with 30 threads of gold, and ended with 30 threads of black, increasing the black by 3 threads every inch.
Recently I had used the drawdown of the plain back cord from Davison’s book for one of my “Right from the Start” articles in Shuttle Spindle & Dyepot. This seemed a good opportunity to weave the Plain Back Cord Joseph France #23, threading #25; I used the suggestion of cramming in the reed 4 threads out of the 6 of the repeat. Here is the drawdown:
I wove the weft-dominant side on top on the loom. I rearranged Davison’s treadling so I could treadle across the six treadles by repeating the tie-up.
I changed my mind about the weft several times. Ultimately, I decided that a textured weft would capture the idea of the prominences. I also decided that doing a gradation in the weft could be better than a solid color. I chose a rayon boucle from my stash for the gold. I didn’t have enough of a single textured black, rather several ones that I liked, so I decided that I could change the black every so often.
For the gradation I divided the length of the scarf into 9 segments, in parallel with the threading; each was approximately 7.1”. I started with the gold, and increased the amount of black by 10%, except for the first and last segment where the increase was 20%.
I was busy weaving samples on my 8-shaft loom for my Convergence® seminars, so the scarf set unattended for a while. Finally, it’s done! I machine washed it and machine dried it on low to encourage the cord to be more visible.
Here is the scarf, showing the weft dominant side:
The close up below is the warp dominant, showing the cords. The texture from the black yarn is also visible in the close-up.
The next eclipse in the US will be August 23, 2044………. We may have to go elsewhere before then… Spain, August 12, 2026?
Happy Weaving!
Marcy
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Ever Changing Times |
Marcy Petrini
May, 2024
Aretha Franklin’s song applies to weaving!
I was writing the block monograph for my Convergence® seminar and I decided to add basket weave thinking “when one block weaves weft floats, the adjacent block weaves warp floats.”
The blocks may be more obvious if I showed a figured basket weave, which is a classification I learned from the book More Than Four. A Book for Multiple Harness Weavers by Mary Elizabeth Laughlin. What we often weave, same number of threads per shaft, is a common basket weave; if we combine basket weaves with different number of threads, we have a fancy basket weave, which can still be woven on two shafts. A figured basket weave is a combination of common and / or fancy which require more than two shafts.
I knew I had woven a table runner with a figured basket weave a long time ago. The task in front of me was to find either a picture of the runner or the runner itself so Terry could take a picture. Then I had to find the drawdown.
The first task proved to be easier than I thought. I guessed that the runner was woven in the early 1980s, so I checked Terry’s directories from those years, and I found it. A close up of the fabric is below.
I fill an Excell worksheet for every project I do now, but I wasn’t sure how long ago I started. Looking at my computer directory for projects, I found my computer files started in early 2000’s.
Before computer worksheets, I had used manual forms stored in many three-ring binders. However, I have discovered looking for other projects that I wasn’t always complete with the information, so I was concerned that my search would yield nothing useful. I started with binder #2 labeled 1980s (I started weaving in the late 1970s).
And there it was, in the middle of the fat binder, all the information about the figured basket weave! It turned out that in addition to weaving the runner, I had woven samples for the 1983 exchange of the Chimneyville Weavers Guild (as it was called then).
The information brought a smile to my face! Below is the scan of the manual drawdown. I had done only one repeat of the threading because filling boxes is time consuming, but I added three threads of the next repeat, to see what happens at the junction.
I had written a computer program to do drawdowns. Once I had the manual drawdown for a small part of the project, I could visualize the rest with the computer printout. Below is a scan of a part of the wide printout that was in the binder. Only certain characters were available on a dot matrix printer back then, so I used a star in the place of a box.
From the printout, I could see the overall pattern.
It’s hard to believe now, but some people objected to a computerized drawdown. The complaints were that handweaving was done by hand, computers shouldn’t be involved. Other people were also writing drawdown programs, so I wrote an article in defense of these programs, “Computers Don’t Weave” in Shuttle Spindle & Dyepot, XIV:3:62-65, Summer 1983.
For the monograph, I redid the drawdown using software, shown below.
It was fun going down memory lane. It reminds me of ever changing times.
Happy Weaving!
Marcy
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Wichita - Here We Come |
Marcy Petrini
June, 2024
Three shorts weeks from today (Monday May 17th as I write), we will be heading from Jackson, MS to Wichita, KS Convergence® 2024 in our vehicle full of manographs for my classes and photography equipment for Terry to take pictures as a conference volunteer.
As I review and edit my monographs to be used for my seminars, I think about the “Up and Down the Twill Shaft Escalator.” Why worry about going from a four-shaft loom to an eight-shaft loom? Just opening Carol Strickler’s book gives many eight-shaft twills from which to choose. However, thinking about the topic allows me to focus on options for the different kinds of twills.
Let’s consider the straight twill below.
To convert it to eight shafts, we couldn’t just extend the treadling steps as the resulting floats would be six threads long, perhaps not too long for some setts, but so unbalanced that the float could sag.
One solution is to delimit the floats by adding parallel twill lines. The one shown below is a 3/2/1/2 twill, called a regular twill because each treadling step produces the same ratio of warp and weft across the pick.
But why not an irregular twill, sometimes called a fancy twill? Below is one I quickly sketched out. Think of the options. And we wouldn’t need to stop at eight shafts!
If you have a multishaft loom (greater than four shafts, that is), why would you care to decrease your design to four?
This is what happened to me. I really liked the 40-shaft twill I designed for a shawl “Ripples in Knoxville” which I wore at Convergence® 2022 and shown below.
I saw a flower that reminded me of the concentric circles in the shawl design and I wanted to use it for a scarf. My four shaft loom was available, so I scaled down the twill to four in the design below. Simpler, but still effective.
I weave a lot of twills, but usually not block structures so much. I spent the last several months weaving 8-shaft samples for my “Not All Blocks Are Created Equal.”
Can you figure out what these two structures are?
For most didactic sessions, the teacher, or leader as we call them at Convergence®, is relatively in control: there is a plan, a certain amount to be explained, work to be shared. Sure, questions come up, explanations may need to be clarified and sometimes a query needs further investigation. But basically, the teacher is in control.
Not so with the seminar “Can We Be Inspired by the Inspiration of Others?” The artists are in control! What inspires each one of us is an individual matter. Understanding what inspired others opens up another window into creativity. I can’t wait!
What inspiration comes to you from this picture? (NOT one to be used in the seminar).
See you at Convergence®!
Marcy
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The Fabric Determines the Structure But You Must Know the Structure |
Marcy Petrini
April, 2024
When faced with an unfamiliar structure, I generally do a drawdown which allows me to break it down starting with the Emery classification.
Glance a drawdown without writing it? That’s exactly what I did recently – and got it wrong!
I received a drawdown from a weaver asking me to figure out what a structure called Eskelhemsdrällen may be. Unfortunately, my software couldn’t read her wif file (I do need to upgrade!) but she sent me the pdf shown below:
It came at a particularly busy time, so I looked at it and I thought that carefully inspecting it would be enough. This is what I decided:
- By Emery classification the fabric is a “Rectangular Float Weave Derived from Plain Weave “ – blocks formed with one warp and one weft.
- Adjacent blocks are not combined in the treadling, thus it cannot be a unit weave, for example, Bronson Lace.
- There is plain weave across the width of the fabric and down the length of the fabric, which is typical of huck.
Scandinavian weavers do imaginative arrangements with huck, so I decided that it was huck.
But, in fact, it is Spot Bronson, the way I learned it many years ago.
The partial drawdown below and the one in the pdf are sinking shed. All the drawdowns that follow for the various structures are rising shed. All my looms are rising shed, so I find myself thinking that way. Of course, as always, the other side of the fabric is the opposite shedding mechanism.
Where did I go wrong?
I went wrong by using the plain weave along the edges as a characteristic and not remembering that one shaft – in this case shaft 1 – is common to all the blocks in both Bronson Lace (aka Lace Bronson) and Spot Bronson.
The Eskelhemsdrällen in the pdf is on more than four shafts. Plain weave can be added to just about any structures by using extra shafts, so the plain weave along the edge should not have led me to conclude that it was huck.
It is important to realize that Eskelhemsdrällen is NOT Bronson Lace. That part I did deduce correctly.
Let’s compare and contrast Bronson Lace with Spot Bronson first on four shafts, than on more.
The next drawdown is Lace Bronson on four shafts; there are two blocks, here repeated in the threading. Plain weave is woven across the fabric by alternating the two tabbies: shaft 1 vs. all other shafts. The tabby on shaft 1 is used in treadling every block.
Its most distinguishing characteristic is that blocks can be combined in the treadling.
Shaft 1 alternates with pattern shafts, but the float of each block is delimited by shaft 2.
Because of the tie in shaft 2, blocks are separated by one thread, most clearly visible in the lower portion of the drawdown where the blocks are treadled together. It’s that separation that allows the blocks to be treadled together, avoiding a long float.
If we sacrifice shaft 2, we can add a block. That’s exactly what Spot Bronson does. In the drawdown below, we see that the blocks are still threaded shaft 1, pattern shaft, but now the pattern shafts are 2, 3 and 4, giving us three blocks. The float is no longer delimited by shaft 2 as in Lace Bronson, rather, the float stops when the pattern shaft of the next block is encountered. The tabbies in Lace Bronson are still shaft 1 vs. all other shafts. The shaft 1 tabby is still used in treadling with every block.
In contrast to Lace Bronson that has one thread separating the blocks, those in Spot Bronson are “stacked” – since shaft 1 is in common with all the blocks, the end of one block is at the same point as the beginning of the next. This is visible in the drawdown.
The other consequence of not having a tie shaft in Spot Bronson is that the blocks of the same type (weft or warp floats) cannot be woven together, it would result in a long float over those blocks, as shown in the drawdown when treadling the first two blocks together.
Thus, Lace Bronson is a unit weave, Spot Bronson is a grouped weave, the same category as huck. It’s unfortunate that this distinction is not always clear. I hear people refer to the structure as “Bronson” – which Bronson?
In huck, as in Spot Bronson, blocks of the same type cannot be combined in the treadling, as shown in the drawdown below, however, the reason is different: to weave plain weave, the tabbies 1 & 3 and 2 & 4 alternate. The blocks with different tabbies cannot be treadled together because 1 & 3 and 2 & 4 would have to be combined for a tabby.
However, the fact that blocks cannot be treadled togethers puts huck and Spot Bronson in the same category.
The Eskelhemsdrällen that my pen-pal sent me is on more than four shafts. Let’s expand our structures to more shafts.
With eight shafts, Spot Bronson has seven blocks, shown in the drawdown below. With more blocks available we see that non-adjacent blocks can be combined in the treadling, adjacent blocks cannot; this is the same situation as Spot Bronson on four shafts, where each block is always adjacent to the others. Treadling adjacent blocks would produce a float over the two blocks.
Treadling together non-adjacent blocks can also be done with huck on more shaft than four, shown in the drawdown below. Adjacent blocks cannot be combined because they have different tabbies.
It is this characteristic that results in the most important difference between Spot Bronson and huck: adjacent blocks of different types can be treadled together in huck, but not in Spot Bronson. In fact, this is huck lace, in the drawdown below. This is possible because the tabbies are shared, that is, block A woven with weft floats has the same tabby as block B woven with warp floats.
In Spot Bronson, weft and warp floats can be woven on the same side of the fabric. The tabby on shaft 1 is used in weaving weft blocks; the tabby with all the other shafts is used in weaving warp floats, the two combined activates all the shafts!
The other characteristics are not so unique. These weaves are classified as “Rectangular Float Weaves Derived from Plain Weave”, thus most, but not all of them, can be surrounded by plain weave.
The Eskelhemsdrällen drawdown has plain weave along the edge, but with multishift structure, we can use one or two shafts, depending on the circumstances, and add plain weave.
Furthermore, if we want two, rather than three blocks in Spot Bronson, we can have plain weave down the selvage edge, as shown in the drawdown below. It’s still Spot Bronson.
When I was originally studying these weaves, they were often lumped together as “lace weaves”, a term that my lace making colleagues argue we shouldn’t use, because we cannot weave true lace. I prefer the term “lacey weaves.” The mantra we used to differentiate them was: one thread between blocks for Lace Bronson, blocks abut for huck, and one shared thread for Spot Bronson.
But even that mantra doesn’t hold true. Here is a Scandinavian huck with threads overlapping!
Below is a drawdown for droppdräll from Practical Weaving Suggestions One Color Upholstery Fabrics, Vol. 2-58, by Edna Olsen Healy and published by the Lily Mills Company, Shelby, N.C. It is in the public domain and is available from the University of Arizona at this link:
https://www2.cs.arizona.edu/patterns/weaving/periodicals/pws_58_2.pdf
It was brought to my attention by my study group colleague Peggy Cole.
So, here is a summary of how to differentiate between these weaves:
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Tabbies |
Shafts 1, |
Shaft 1 |
Shaft 1 |
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Tabbies |
Odd vs. |
Shaft 1 vs. |
Shaft 1 vs. |
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Treadling blocks with |
Only |
Only |
Any |
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Treadling blocks with |
Yes, huck lace |
Not possible |
Not possible |
I hope comparing and contrasting these structures will give you some ideas on how to design with them.
Happy Weaving!
Marcy
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