Of course, my first instinct was to see how it would degum...
The strands are perfectly even. The individual strands are 30 denier, which is apparently 14 "ply" of the original filament - which means that the filaments should be close to the same size as bombyx silk.
But, I didn't know if spider silk even *has* silk gum. It's not made from fibroin and sericin - it's made from "spidroin."
So the experiment - to throw and degum a skein of the synthetic spider silk, to see if it behaves at all like silkworm silk.
First, I threw a four-strand tram. This is moderately twisted with an electric spinning wheel, so that the fibers will all play nicely together.
This is the thrown spidrex on the reel, where I've wound it into a skein. The filaments are wiry and slightly golden. They feel exactly like raw bombyx silk. The curly piece is some of the single filaments, for size comparison to the thrown tram.
When I took the skein off the winder, it twisted up very tightly. No surprise there - this is a twisted singles, so it's got a lot of energy.
Fortunately, once I lowered it into the hot degumming solution, it loosened up. Just like with bombyx silk, the thread spread out, making a cloud-like puddle of silk. The spoon is in there to keep the center of the skein open.
This is a comparison of the finished degummed strand (left) and the raw filament (right.)
Here, you can see how the tied end of the skein has fuzzed out. I can't count them, but I imagine that each strand has split into its 14 component fibers; the fuzz is about the right weight for that.
You can see that it catches the light very well; the finished strand has a sheen very similar to reeled bombyx silk, although the color is closer to that of tussah. It's also very soft - the photos can't show that, but it is so much softer than before. It's also got the slightly snaggy hand that reeled silk does; it catches on rough spots in the skin, because the fine fibers are so long.
Overall, a very successful and thoroughly enjoyable experiment. Next (probably on Saturday) will be to see how it takes dye!