Welcome to my new Stitching Blog. It’s like my regular blog except all about quilting and embroidery. I’ve separated the two, because I get the feeling that people interesting in my science writing and app-making activities may find all the stitching a bit tedious, and vise-versa. Also, I have taken the liberty of using the same list of subscribers to my stitchcam as the list to be notified (via rss feed) when there’s a new post on this blog. I figure if you’re interested enough in stitching to get real-time notifications of a quilting machine running, you’re probably interested enough to hear about an occasional blog post.
So without further ado, my first new stitching-related blog post. I’m afraid it’s a rather technical one….
One of the big problems with fabrics and quilting is that fabric is not a proper engineering material. It’s stretchy and sloppy and never goes exactly where you want it to. The situation only gets worse when you add batting to the equation.
We’ve been experimenting with extra-thick batting, as much as two inches thick, and have had a problem with the resulting “quilts” not lying flat, because some parts of the pattern shrink the dimensions of the fabric more than other parts, resulting in a sheet that is internally stressed.
You might think it’s a simple case of more stitches equals more shrinkage (as it more or less is with embroidery), but this is not the case.
To see why, consider a cross section of a quilt with different spacings between the quilting lines. When there are no lines, the fabric on the top and bottom are flat, and the piece overall will be just as long as the fabric originally was. As you add more lines, the fabric is forced to go up and down, so even if the fabric isn’t physically compressed, the piece overall will get shorter.
Here is a schematic illustrating this fairly obvious fact. Clearly if the lines (the top and bottom fabric) stay the same length, the overall length of the quilt must get shorter.
But what if you keep going? There is a fallacy in this drawing: The thickness of the quilt is staying the same. Clearly the following is NOT what happens if you add even more lines:
These diagrams get more and more absurd, because of course what actually happens is that the batting gets hammered down, the piece gets thinner overall, and the fabric goes back to being flatter. And that means the overall piece should start getting LONGER again, at a certain point. That’s what I wanted to confirm and quantity, so I had Behemoth stitch twelve different test strips like these, each about a meter long:
Here is the diagram again, except this time the widths shown are real, measured widths from my experiment. (In the diagram below, the number of humps is real and the relative lengths are real, but the thicknesses are schematic, because I didn’t measure the actual thicknesses):
As you can see, there is a minimum length around 30 humps, and by the time you get to 200 humps (0.5cm line spacing) the thing is well on its way back to its original length.
Here is a plot of the lengths as a function of line spacing (the right-most data point represents infinite line spacing, in other words the original fabric length):
The interesting fact about this is that, because there’s a minimum, there are going to be two ways to get any given amount of shrinkage, a large-spacing way and a small-spacing way, one on either side of the valley. In order to get a quilt that lays flat, you don’t have to keep all the spacings the same, you can have zones of stitching width spacings on either side of the minimum.
These tests were all with lines in only one direction, but what if you add crossed lines in the other direction? I did a second set of twelve test strips with lines going in both directions, like these:
The following graph is a bit harder to read. The horizontal axis represents the line spacing in the direction of shrinkage (just like in the graph above). The vertical scale is again overall length of the piece. The lines connecting data points represent sets of similar spacing in the lines going the other direction. The bottom set has no cross-lines (i.e. it’s the same data points as the graph above, except a smaller number of them shown). As you go up, each line represents more and more closely spaced cross-lines. The data points are labeled with the line spacing in the shrinkage and crossed directions respectively.
The result is as expected: The more closely spaced the crossed lines are, the less shrinkage there is, regardless of how closely spaced the lines are in the shrinkage direction.
Now all we need to do is actually use this information to make something pretty that doesn’t warp…. In the mean time, we’ve been experimenting with the other solution: Stretching on a frame.
This quilt is “double-quilted”, using the term Nina invented for a thing I decided to try because why not. It’s basically a quilt on top of a quilt, so we can have a secondary level of relief that isn’t hammer down overall. I’ll write a full blog post about this technique later, but here’s a closeup that gives an idea of what it looks like:
Was all the quantitative measuring useful? Maybe…. So far I’ve used it only to create an interpolating function that I have used in some calculations involving how wide to make flaps that wrap around the wooden frame holding up stretched quilts like this. Hm, that’s probably another blog post too.
I am a better line processor than any algorithm we currently have access to. Behold what I turned into a SINGLE LINE by hand:
Look upon my works, ye mighty, and despair!
Many people think we’re using Mathematica to do the drawings of our Quilt Money. We’re not! I am drawing all this stuff by hand. Theo uses Mathematica to route my drawings that contain T-intersections, but I’m learning to make my drawings single lines without T-intersections by hand, because they route much better that way. Everything below was drawn by me, by hand:
Only a few bits (the seals and part of the border) need to be routed in Mathematica. Everything else I drew as single paths. Which is quite a brain-hurter, lemme tell ya. Here’s a screen capture of me working on this same project last week:
I could do this much more efficiently now, using what I’ve learned since then. Which is good, because the better I get at this, the more I can help someone else create algorithms to automate this kind of work.
And yes, at some point we hope to offer an affordable $100 Quilt. But first I have to get the design right, and then our potential partner has to be able actually produce it without losing money. We’re working on it.
Our quilted money is one of the few things I don’t share source (in this case, vector) files for, because currency isn’t exactly like other culture, as I explain here.
A friend recently refinished my Singer parlor cabinet (pix later) and asked to be paid in quilt. He’s a fish scientist, so naturally he wanted a fish quilt.
It’s a little over 6′ by 3′ – I haven’t measured it actually. Also the photos are all a bit distorted because I couldn’t shoot it straight on. Instead these are all taken of it lying on my cutting table.
The technique is Trapplique. The parts were stitched on the quilt plotter. I cut them out, then basted and satin stitched them down with my sailmaking machine.
It has a sequined and beaded eye.
The quilt above belongs to Niels the fish scientist, but the most efficient use of materials with this design was to make 2 fish’s worth of trapplique parts in one stitching. So I assembled a mirror image fish for myself:
PaleGray Labs being the textile art collaboration of me and Theodore Gray. First up, we have a photo of Mathematician Ian Stewart holding up PaleGray Labs’ “Fibonacci Sequins” quilt Theo just gave him in London:
This was designed by me and Theo using a Mathematica tool he created for that purpose, stitched on the new quilt plotter, and bound on my 100-year-old Davis Vertical Feed treadle machine. I hand-sewed on the sequins and beads. This was a test, but we plan to make more of them, including large bed quilts.
Below are some initial experiments with the quilt plotter. We’re still getting the hang of this thing, and working out some software issues that will require communicating through a Chinese interpreter some time in February after Chinese New Year vacations are over.
All stitchcoding by Theo using tools he built in Mathematica. Above we have fibonacci spiral fractals, a big guilloche pattern, and a modified dancing Reena Shah cycle from Sita Sings the Blues. All just tests, because the machine ripped the fabric before we learned to let it “cycle” on before moving the head (a problem that could be fixed with improved software, but until we get the ear of the Chinese software company that controls its operating system we just have to be very careful and do a lot of work-arounds).
Here’s my treadle-operated Davis Vertical Feed, which I am in love with. It makes binding almost a pleasure, a physical game of skill, a kind of meditation. If it weren’t for the time it takes to cut and iron the binding strips, I could see binding all PaleGray Labs quilts with this. (I’m also experimenting with bias tape and a Suisei binder attachment on my Singer treadle and Featherweight, which have the necessary mounting screw holes but lack the genuine walking foot that quality binding needs). Behind the Davis is the new 20″ long arm zig-zag machine, designed for making sails but which I intend to use for trapplique. It’s a powerful beast but we don’t get along because something’s wrong with its tension. The company is sending me a new tension assembly which will hopefully fix the problem.
The domain palegraylabs.com currently just reroutes to the “Quilting” category of this blog. Hopefully we (meaning I, helped by Webmaster Ian) will design a nice web site of its own soon.
I recently dug up, scanned and restored this cartoon I drew in 1984 for the Uni High yearbook. It makes me nostalgic not for school (for which I still carry much resentment*) but for the glorious escape drawing provided those years. There were no art classes at Uni while I was there, for which I am eternally grateful. While my liberal friends are mostly “arts education” boosters, I owe my survival to Art staying beyond the reach of school, teachers, and institutionalization. School ruined math, literature, physical exercise, social interactions, and pretty much everything else that could be beautiful – thank doG it didn’t ruin drawing too.
*Dropping out of the University of Illinois at the end of my Sophomore year was the first Great Decision I ever made. My second Great Decision was freeing Sita Sings the Blues and dropping out of Copyright. I’ve only made two Great Decisions in my life, but they’re plenty. Dayenu.
Today’s embroidermation features a rotoscoped dance outtake performed by Reena Shah about 7 years ago for Sita Sings the Blues. Theo coded the stitches and the animated sin wave loop background. This is designed for larger quilts, but this version is tiny as it was stitched on our embroidery machine.
I sewed the 16 panels together like so:
The cycle is actually 13 frames long – an annoying number for animation. The final 3 frames are repeats so it could be a 4 x 4 square. Finished size is 16″ x 16″.
The source animation (a vector file sequence) was adapted from my short segment for the upcoming feature film “The Prophet.” That will definitely not be rendered in Embroidermation, but the Tree of Life is such a classic, traditional embroidery motif it was just crying out to be used in this test.
In addition to stitchcoding, Theo hooped and ran the machine on all 96 frames, and then he made them into a flipbook.
Theo hand-stitching 96 embroidered frames into a flipbook
Because he’s crazy, that’s why. He even crafted a copper rig to cut out the frames precisely, and register them for photography (he photographed them too).
Really this is Quiltimation, the result of our embroidery/quilting/trapplique techniques. Here’s a single frame without all the .gif compression 8-bit color artifacts:
The trapplique technique was a lot of work, requiring multiple hoopings for each frame, as well as precision cutting and placing. We probably won’t do more of that. Our next project is more traditional embroidery with just one color of fabric and multiple colors of thread. Whole lotta math required to make this work, which is fortunately Theo’s department. Meanwhile I’ll stitch together these 12 frames into some sort of viable wall hanging.
Someone has been emailing me saying they REALLY want to buy an original Sita Sings the Blues painting. These have been in storage since I moved from New York to Urbana IL last year, but I just excavated them and took some crappy photos (reflective glass! Wide-angle pocket camera lens!) for her to choose from. Click thumbnail for hi-res jpeg.
If anyone else wants to buy an original painting let me know: nina underscore paley at yahoo dot com. The outside dimensions of the wooden frames are about 12″ x 14.8″. They’re about $1000 each, give or take for more or less complex/competent paintings.