Quantitative Stretching

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. 








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.




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.