Following my post 'One Thread Fits All', I had a very interesting email conversation with Michael who left the following comment
I've got a question. I don't have much experience with Japanese flat silk. I have handled a piece of JEC Flat Silk that Mary Corbet sent me, but that's it.
It appears that the sugas are very slightly twisted. I haven't actually sat down with a pin and a piece of tape and figured out how many twists per foot, but it looks like they've got just enough twist that it's easy to separate the sugas (i.e., you can pick half a thread, or a third of a thread, and it hangs together well.) Is this typical of the flat silks you're using? I can't really tell from looking at the photos; even with the macro, I can't tell if the sugas are distinct, or if I'm just imagining it.
I'm thinking that this would be part of their strategy for managing the silk "flat" - otherwise, it's a hairy beast to get it into and out of the dye kettle without massive tangles.
Well I haven’t actually sat down with a pin either, but I very carefully unreeled a fresh length of silk and took a good look at it. Firstly, I have always understood that the silk we use is totally flat (that is to say that the sugas are not twisted together at all) and having examined it, I think that is the case. The problem is, it is very easy to introduce twist, and indeed the method by which we secure the tread to the awl introduces 2 or 3 twists to begin with! I then went about separating the thread into single sugas (there are 12 sugars to each thread). I purposely selected a thread that separated easily, in my experience pale thread are more obliging than darker ones.
As you can see, each sugar is very fine. The thread on the far left is DMC cotton (as it comes with 6 strands loosely twisted together), beside that is a strand of silk as it comes from the reel, then the 12 individual sugars and, on the far right, a single strand of DMC cotton. If you click on the picture for an enlargement you can clearly see that the DMC is a two-ply thread with a fairly tight twist. Each sugar is made up of many silk strands, which (I think) are lightly twisted together. I have heard that in China they use a single suga for silk painting. Now that must take some patience!
Before I go, I need to pass on some news. Most of you will already know but incase you have missed it, SharonB has moved her blog to a new blog 'Pin Tangle'. Wether you are a regular or occasional visitor to Sharon'sw blog, you will want to make a note of her new site.