But there were some dye questions in the comments, so here you go:
For yarn sources, keep an eye out for sources. Elann.com has some nice stuff for reasonable prices; local stores run specials all the time. When I started my experiments I used Paton's Merino. Superwash gives you a slight advantage, in that you don't have to worry about felting it, but it's not that big a deal. Buy what's cheap and go for it. (You of course need to use animal fibers or silk, for the food coloring to stick properly.)
For temperature, I usually set my roaster at 250 F and boil the yarn for a bit. If you're using superwash, it doesn't matter how fast it heats up; if it's NOT superwash, raise the temp slowly over a half an hour or so, to avoid felting or shrinking. Keep the yarn in that heat zone for at least ten minutes, if you want it to be colorfast. Oh - and if you are using silk, don't heat it over 180 F; it ruins the sheen and makes the fiber fragile and brittle.
As for creating tweed yarn, well, that's really a result of the spinning process, so nothing you do with dye is going to create a tweed. However, if you get a yarn spun from different fibers that take up the dye differently, you can get a slightly tweedy, marled effect. Wool/cotton blend is very dramatic, because the cotton doesn't take up the dye hardly at all. Silk/wool blends are very nice, as is cashmere/wool, and alpaca/wool. They all take up dye differently and they all look different when dyed in the skein. (Elann.com also has lots of nice wool blends for reasonable prices.)
That's it here. I managed to avoid working on the Mystery Knit all day. And I've ALREADY altered my next-sweater plans; not "Tut Tut", but something else based on Chinese ceramics. Not only can I sell the pattern, I can submit the sweater itself to the state fair. (Yes. I'm a glutton for punishment.) I will get a blue ribbon out of them before I move. Or else.
I think June will be the month for the Humongous Bendigo Order. The husbeast has already been warned. (He's all for it - part of the order is his Christmas present, and I told him so.)