Heatherly asked, in How do you spin beads into yarn? (Part 2) if I add extra plying twist to keep beads in place.
Wow, I'd forgotten that is one of the things I think about when I'm spinning beads into yarn! Here are my thoughts on the topic ...
If I have a higher twist yarn, thus more tightly plied, there are more twists to make sure the beads don't travel along the length of their thread (or, if I'm spinning them directly onto/into the yarn, along their ply). So I do tend to go for a fairly tight ply, nothing too loose. I also tend to spin no thicker than a DK-weight 2-ply, 15 wraps per inch, so the beads aren't overpowered by the yarn. That said, if you use a larger bead, you could spin a thicker yarn. The main thing to consider is if the bead might wander.
A secondary concern is how well the beads are held in, should the thread break or when you (gasp!) cut the yarn once it's been knit, woven, crocheted, or otherwise crafted into an item.
I think all that is why my favorite way to spin beads into yarn is to have a thread core with pre-strung beads ... I capture the thread as a core in the single, so it is very well "trapped" in place as are the beads it holds. Also, I only do that for one ply -- the other ply is just spun plain, so I don't need to worry about the Murphy! moment of two beads meeting up when plying. (With apologies to anyone whose name is Murphy ...)
Now, all that said, I don't put an over-amount of plying twist in for the singles twist. If I want a higher plying twist, I make sure I have enough singles twist to compensate for it -- my end goal, being a knitter to the core, is to end up with a balanced yarn.
Heatherly, thanks for asking!
If you have a question about spinning beads into yarn, spinning a balanced two-ply, or all the Murphy moments of my spinning experience, feel free to comment here, email, or contact me.