Tuesday, April 24, 2007

Jacquard Fever

Last weekend was the CNCH annual conference, held this year at Asilomar Conference Grounds in Pacific Grove. I took a 2.5-day workshop with Alice Schlein on using Adobe Photoshop as a design tool for dobby or jacquard weaving. The good news is that I learned a lot and now have some new design tools. The bad news is that I now have a serious case of Jacquard Fever. Gotta have one.

To reinforce what I learned, I spent some time today working with a photograph of some dogwood trees in bloom taken by my sister Barbara. Here's a portion of the photograph, in the original colors:

After a little time in Photoshop, working with brightness/contrast and color levels, I indexed the photo to 7 colors. Seven is the right number if you intend to weave a picture using shaded 8-end satins because with 8-end satins there are 7 possible combinations: 1 thread up and 7 threads down (written as 1/7), 2/6, 3/5, 4/4, 5/3, 6/2, and 7/1.

For the purpose of this example, assume that the warp threads are black and the weft threads white. So a thread "up" means that where the warp and weft intersect, the warp is on top of the weft, so what shows is black. Conversely, a thread that's "down" means the warp is under the weft, so what shows is white. So 1/7 satin is mostly white, while 7/1 satin is mostly black.

Okay, here's the photo in 7 colors (they all happen to be shades of gray):

Then, I assign one of the 7 satin patterns to each of the 7 colors by "filling" the color areas with the weave pattern. I assign 1/7 satin to the lightest color, 2/6 satin to the next lightest, and so on to 7/1 in the black areas. Here's the result, all ready to weave. Each pixel in the photograph has become a point where a single warp and a single weft intersect, and if an area has mostly warp on the surface, that area is dark; if an area has mostly weft on the surface, that area is light. Note that there aren't any completely white areas in this version, or any completely black areas. That's because if no threads are "up" or if no threads are "down" you don't have cloth, just a mess of tangled loose threads. There has to be at least one intersection (or transition from "up" to "down" or vice versa) in that group of threads to make woven cloth.

Now, if only I had a Jacquard loom so I could weave the photo for Barbara's birthday present...

In the meantime, I'll do some practice on the techniques for creating designs for my 24-shaft dobby loom in Photoshop, and if I come up with anything that looks interesting, I'll post pictures. Plus, there are still four wood grain scarves waiting to be woven.

1 comment:

Beryl said...

I'm afraid to even get into doing all of this -- a jacquard is just too tempting. What software did you use?