Back when I was growing up, the then-new manmade fibers were heavily touted as "miracle fibers" -- those fabrics that were wash 'n wear, required little if any ironing, either never showed stains or you could get spots out easily, and lasted virtually forever. In time, we learned most of that simply wasn't true. The manmade fibers didn't hold up the way they were supposed to or developed problems of their own. And who wanted to wear lime green jacquard polyester leisure suits, anyway?
Now that's ancient history. Today's miracle fiber, IMHO, is silk. They used to say you had to dry clean silk, but that too was hogwash. Fact is, I had my share of sumptuous silk blouses ruined by dry cleaning in the 1980s. Among it's numerous virtues, silk is very hand washable, plus it's nearly indestructible. Silk is also light weight and amazingly warm, it's hypoallergenic, it dyes magnificently, and it comes in a wide variety of textures and finishes. Is there anyone out there who doesn't absolutely love silk?
I've been spinning silk, almost exclusively, for the past eight years. Originally I switched to silk from animal fibers, when I found I could no longer wear wools -- even very fine merino wool -- because they caused me to itch and made my skin crawl. At first I moved from sheep wool to alpaca, but that was way too warm and still somewhat itchy, and eventually I went down the list of finer and finer animal fibers until I found myself so unbelievably allergic to angora that I can't be in the same room with the stuff. So enter silk in my life, and I've never looked back.
Although all silk comes from silk worm cocoons, the first division in types of silk is whether it has been cultivated or harvested in the wild. All, or nearly all cultivated silk comes from the Bombyx Mori moth, hence cultivated silk is simply called bombyx, or alternately mulberry silk, because bombyx moths are raised exclusively on mulberry leaves. Cultivated silk is very white and lustrous.
Wild silk is called tussah or sometimes muga depending on the species of moth, and there are many silk moth species in the world. What distinguishes all wild silk is that it will range in color from honey to a nearly cinnamon color, depending on what the moths eat. The more tannin in the moths' food supply, the darker tan the silk will be. Of course, these days you can get bleached tussah, but even though it can be disguised to look like bombyx, there are distinct differences in the way the two silks feel. Tussah or wild silks are just slightly crimpy compared with the amazingly straight bombyx silk fibers; they're fuzzier, they're matte in finish, and they're slightly heavier. Also slightly stronger.
Regardless of whether they are cultivated or wild, silk cocoons are processed to get silk fiber for spinning, and subsequently for silk yarn and silk fabrics. It all starts with those fine strands of fiber that create the cocoon. In the processing of cocoons another division occurs, and that is between long silk fibers and short fibers or noil. The long straight fibers are combed together to become top or sliver (pronounced with a long "i"). Silk top is heavenly to spin with, it practically spins itself. Typically you'll use the long draw spinning technique. You can spin it extremely finely, or not, the fibers are long and straight, and the yarn is so strong -- even the very finest yarn -- that you can easily cut your hand trying to break it!
The short noil fibers might be carded into roving, or spun as is. Usually silk noil fiber has bits of cocoon in it, or small pieces of whatever the cocoon was hanging on out in the wild. It looks a lot like cotton fiber. It's a completely different experience spinning silk noil -- because the fibers are so short you must use the short draw method keeping your hands very close together. And you'll typically spin a chunky yarn, although it will weigh almost nothing.
Cocoons also might be made into hankies, which are then dyed, separated into individual cocoon layers, and spun. A hanky is a flat square of silk comprised of approximately 6 to 8 cocoons that have been degummed in water and soda ash, had the worm pupa removed, and been stretched over a 10" x 10" frame to dry. Hankies have both long and short fibers in them so when they're spun up, the resulting yarn will have tiny slubs of short fibers. Spun up, this is raw silk textured yarn.
I should clarify that my focus is primarily on spun silk, because I am a spinner. There's also an entire industry devoted to reeled silk, that creates unbelievably gorgeous and extremely expensive yarn and fabrics made of numerous filaments of silk being unreeled together from individual cocoons and made into thread, rather than being spun together.
The silks just mentioned -- bombyx and tussah top, hankies, and noil -- are what I spin. I often combine a ply of one type of silk with a ply of another to create interesting and unusual yarns. For example, a chunky noil ply with a very fine bombyx ply. I also often hand card angelina fiber and/or weaving thrums into the silk noil, then ply that with fine bombyx, for a really unique, glitzy silk novelty yarn.
For earlier posts about my work with silk -- spinning, weaving and/or dyeing -- go to the compilation here. For a really terrific website devoted to silk worm raising and cultivation, visit Michael Cook at WormSpit. For great source info on using silk, see Treenway Silk's website. And check out my Etsy store for silks to spin. Enjoy!