If you are working with beads that are placed on stitches (with a crochet hook), you don’t need to worry as much about your yarn’s fiber content and structure but if you are working with prestrung beads (like in Circo Mystery KAL and many other of my designs), please read this information closely!
Since sliding beads down your yarn causes friction and can abrade fibers, it’s important to choose a yarn that is strong and can handle this action. You don't want to spend hours knitting on your project to find out that it looks worn before you even get to wear it!
Yarn with multiple plies and a tight twist will stand up to the friction well. As much as I love single ply yarns like Madeline Tosh Light, or Manos Fino, I tend to stay away from them if I am working with pre-strung beads as I know the yarn's surface will quickly degrade from the bead friction.
Find a yarn with a high merino wool or cotton content, and perhaps even some nylon. I shy away from yarns with more than 5–10 percent silk or cashmere, as those fragile fibers degrade easily.
Some of you might notice that the yarn I worked with for Meta Mystery KAL, Black Trillium Fibre Studio Silken Lace, is 85% Superwash Merino and 15% Mulberry Silk. Typically most commercial yarns use tussah silk, which has lovely sheen and great drape, but is not incredibly strong. Tussah silk fibers break very easily causing a halo or pilling along your fabric's surface. Mulberry silk is much stronger and that combined with the tight twist of Silken Lace make it a great choice. How did I discover that? I did this test on it:
Do you have a yarn in your stash that you’d love to use for a project, but you aren’t sure that it will hold up to beads sliding along it? Take a strand of the yarn you are considering, string on a few beads, and tie it around your wrist. Wear it like this for a few days, and you will quickly know if the yarn can withstand the friction of the beads sliding along it!
Whenever I design a pattern (or release a Mystery Knit-A-Long) I choose a yarn that is appropriate for the project, I also list other yarns that will work as well. If you aren't sure what yarn to use this is a great jumping off point for choosing a yarn.
Of course, you can always ask in my Ravelry group if you aren't sure the yarn you have on hand is a good choice, or ask below, I'm happy to help!