I’m going to admit a sort of dirty secret here. I used to crochet with Red Heart yarn. Maybe you don’t realize what a sin that is, so let me explain. For $4 you can buy 365 yards of their best-selling “Super Saver Economy” yarn, an acrylic yarn that makes a kind of squeaky sound if you rub it between your fingers.
Then Mom and Dad had this crazy idea to become alpaca ranchers. Pretty much overnight I had access to nicer fiber than I’d ever worked with before. Suddenly I had to pay attention to the different types of yarn out there, not because I was crocheting with them, but because I was making them. It’s an entirely different perspective, one that not only considers the yarn as an end product, but also the steps before the spinning. Let me see if I can explain.
Worsted weight – Until I started spinning, I thought this simply meant thicker yarn. Wrong. Worsted yarn can be any thickness or thinness (though it’s usually right in the middle of the spectrum), what distinguishes it is that all the fibers are parallel to each other in the roving. After the fiber has been carded, it is pulled through a “diz”, basically a button-hole, to make sure all the fibers lie parallel to each other in the roving. The yarn is then spun using a “short draw” technique. The spinner keeps her hands close together as she works, and doesn’t allow any twist to enter the fiber between her hands. Worsted weight yarns are super strong, though not especially soft, and are used for outwear.
Semi-worsted – Most spinners, including myself, produce a semi-worsted yarn. The roving we use is fairly well-organized with all the fiber lying parallel, but we don’t bother with the diz step. The yarn is still spun using a short draw, but it won’t be quite as ‘clean’, in that you may see stray hairs poking out here and there.
Woolen – The prepartion for woolen yarns is the opposite of that for worsted yarns. Instead of all the fibers being parallel to each other and the direction you are spinning, they are perpendicular. To prepare a “rolag”, which is the woolen equivalent of “roving”, you take your carded batt, roll it up and then stretch it width-wise. Woolen spinning uses a different technique to preserve the perpendicular structure of the fiber, called the “long draw”. In this technique, spinners allow some twist to creep into the unspun fiber as they slowly move their hands apart. This twist stops the fiber from organizing length wise.
Woolen yarns are the softest and most delicate yarns. They have a tendency to come apart in your hands as you ply and don’t wear particularly well, but are soft soft soft. They tend to be fuzzy looking, or have a “halo”.
Part of the confusion about different yarn “weights”, which implies the thick/thin quality of the yarn, and the different yarn “types”, which are the woolen/worsted qualities, stems from modern manufacturing techniques that use not-natural fiber that don’t require the same prep.