If you set the caterpillars up on a surface where they can’t find a corner, they’ll make this stuff. It doesn’t hurt them, although it probably frustrates their instincts. After spinning out their silk, they turn into a healthy pupa.
This is the surface of the paper. One of the things I learned from the first run – make sure the silkworms are DONE pooping, really, are you SURE you’re done, before you put them on the paper. You can’t wash it out once it’s sandwiched between layers of silk.
This is how I set them up to spin the paper. There has to be an overhang, so that they cannot crawl down without crawling upside-down, which they avoid. Once they are done spinning, they turn into pupae, often right on top of the paper; then, I put them down in the bottom. A few have managed to climb down there on their own.
Here, you can still see the plastic needlepoint canvas through the silk. As they work on it more, the silk becomes more opaque, and you don’t see the canvas.
This one looks like he’s dancing, or doing Tai Chi. Notice the little “hemmed” edge – the worms tend to pull the silk back from the edge of the canvas base and then silk over it more. It really does look like a turned hem.
I washed and ironed the sheet, which made it shrink and wrinkle a little. I think it looks like leather.
The finished sheet is about the stiffness of paper, although it does have a little bit of a more leathery drape.
If you pinch it, the folds are sharp; it holds a crease well after ironing. I think it would be well-suited for certain origami applications. I know that some of the tribal women in Thailand use pieces of this stuff for applique on their skirts. There is a company called LiveSilk that is working on making a commercial product similar to this.