So one more test that I wanted to try, since I haven't done it yet, is to ply with white.
Now, we all know that if you are using two very different colours, you are going to get a barber pole effect. Not my favourite design in yarns, although I have knit some socks with that kind of yarn, and it actually looked okay. So I am not saying no without at least giving it a try.
I spun up a fine white single on the spindle, naturally. Then I plied them. The neatest thing was the barber pole I got! I liked it! And the thing is that you can easily see how even your plying is when it is lying next to each other -- that angle of the ply really shows itself, and when you have several yarns laying side by side like this, you can see if the angle (therefore your plying) of the ply is all the same. Cool!
Then I knit up a sample tonight with this plied yarn. It's very interesting. Nothing like any of the rest. The white, because of the fine yarns, and the tight ply, produces a speckled effect, and when knit up, it looks quite heathered. The white doesn't interfere too much with the colour of the other single, letting the colour differences show up nicely. The white does tend to wash out the colours a bit, but that is minor in this sample.
So now there is one more sample I need to do. This time, I think this will be the last. No, really. There isn't any more I can do -- after this last one.