As I may have noted before, started out I using cotton embroidery floss to make most of my braids. However, I have collected several nice colors of silk and some lovely bamboo threads, so I thought I'd gear up to work with them by switching to perle cotton.
Now, I first worked with perle cotton when I moved to the marudai, and I didn't like it because it had a twist. However, it turns out that THAT was no. 5 perle. After a couple people on the kumi2 mailinglist recommended No. 8 (which, like larger numbers of wire, is thinner), I thought I'd try that. It is still twisted, but you can use multiple threads to give an appearance similar to kumihimo silk (although not nearly as thin as that!)
The fun thing is that compared to embroidery floss, No. 8 perle works up fast because the scale is so much larger. When I talk about 3-4 strands of embroidery floss, I mean, you take the 6-strand length apart and use 4 of of those...it's TEENSY! On the other hand, four strands of No. 8 perle cotton I can see without my glasses, thus making any problems with the braid really obvious early on.
The big problem for me about No. 8, at least in my neck of the woods, is that it seems to come in white, ecru, off-white, eggshell, light tan, light ecru... well, you get it, not many colors at all. When I came across some in actually non-white colors unexpectedly, I bought all I could, which included red, blue and black (and white, but no ecru :>)
I've wanted to play with kumi and wire, but I had so many more projects I wanted to try first that I never actually gave it a shot. When I found some pre-cut scrap wire, I decided to try a very simple 4 strand braid.
Unbeknownst to me (at that point), very thin wire is recommended for kumi with wire, and then it behaves a bit like thread. Using a bigger wire, means that I did not need the Marudai OR the disk/plate. This is okay if you're only using 4 strands, but I think I'd like some references if I work with more strands.
For my next experiment, I have cut 8 strands 22g colored copper wire, but I still need to contemplate how to kumi without the disk or marudai but still with some reference.