Attend a few fiber shows, and knitting festivals and you are sure to find some handspun yarn that is wonderfully thick, yet still light as air. What is this glorious fiber, and how can I make it myself, you ask. The fiber itself does of course factor into the airiness of the finished yarn, but another contributing factor is pre-drafting the fiber prior to spinning.
When fiber is carded and formed into roving, it can often become very dense and compacted. Also, fiber that has been stored for a long time or dyed after carding can cause difficulty for the spinner. Pre-drafting can resolve this, as well as improve the quality of the finished yarn.
To pre-draft roving, first test the staple length by taking a piece with both hands, and tugging gently with your hands placed closely together. Gradually move your hands apart while tugging until the roving separates into two pieces. This will give you an idea of the staple length of the roving. The longer the staple is, the more it will overlap other staples within the yarn, and therefore it may be spun thinner while still forming a durable yarn.
Once you have determined the staple length, consider what the purpose of the yarn will be. If the yarn is going to be a singles, pre-draft as much as you can, being careful not to draft thinner than your desired finished yarn. This will prevent excessive twist in the singles yarn, which is beneficial if you do not want to reduce its elasticity by drying it under tension.
In the case of a thicker finished yarn, pre-drafting will ensure bulk with minimal weight. Bulky yarn insulates the wearer without sagging under its own weight. For a spinner who is inexperienced, or does not long draft, pre-drafting can be the answer to creating wonderfully light and airy yarn. It can nearly remove, or at least isolate one step of the spinning process. This will allow you to concentrate on twist and take up without the added step of drafting.
To keep your pre-drafted fiber organized, gently wind it onto an empty paper towel tube, leaving about 12” of the beginning end tucked into the tube. Once you have pre-drafted the fiber and wound it onto the tube, it can be stored. To spin this fiber then, take the tail from within the tube, and slide the tube out, this creates a center pull ball of roving that can be placed in a bag or basket to spin from. The roving can also be held in your lap and spun from there.
Another method of pre-drafting is splitting the roving along its length. This works better on silk, llama, suri alpaca, and other very long staple fibers. The splitting method can also be combined with the tug method to achieve a very fine yarn result, such as lace weight singles.