Twist is what holds spun fibres together in a yarn. The finer the yarn, the more twist needed to keep it together. I've been back at my spinning wheel the past couple of days--it's been too long since I spent time regularly at the wheel. I'm working on a small amount of wool-silk blend. I'm aiming for something fine and strong enough to use for embroidery. Here's where I got to this morning:
If I can make yarn like that consistently today, I'll be a happy spinner. I may yet need a little more twist, since I'll lose some when I go to ply it.