Wool is wonderful. It's comfortable and breathable. Knitters love it because the yarns possess a natural stretch.
Above is a new wool fabric being made. It's actually descending from an industrial knitting machine in this picture; you're seeing it as it's being knit and temporarily stopped for inspection. The fabric hasn't had the chance to relax yet, so it's a little stretched out and stressed. But once it's rested, had a nice bath, and is thoroughly dry, the wool fiber will "full" a bit, the ripples in this fabric will be more pronounced, and the sweater knit will be ready for cutting and sewing.
Most sewers know (or eventually learn) the importance of preparing fabric before cutting and sewing. Knowing how to prep is especially important with natural fiber fabrics. Beautiful wool fiber like all protein fiber has a layer of microscopic scales. If the fabric is tossed in the washer, the agitation will cause these scales to bind together; the wool will felt and shrink. High heat and tosses in a dryer will do the same to this material.
Some wool fiber is preshrunk or pre-treated with a chemical solution to make the scales lie flat or to remove the scales from the wool. Wool made with these types of processes can often be machine washed and dried with little to no shrinkage or felting. Fabric care instructions must always be followed, especially with regard to water temperature and dryer temperature. Sustainable methods of producing felt-resistant wool are in development.
So how do I prepare sweater knit wool fabric? Here's my current favorite way of bathing the wool in preparation for cutting and sewing:
- Zigzag or serge any unfinished cut edges on the fabric.
- Add a small amount of mild detergent or soap to cool water in a tub or container. Be sure the container is sufficiently large to hold enough water to completely cover the fabric.
- Add fabric to the soapy water bath. Allow fabric to soak until fabric sinks to the bottom of the container.
- Rinse well in clear water. (Optionally, a natural fabric softener can be used at this point.)
- Squeeze out excess water by rolling fabric in a towel. Or if there's a large amount of fabric, place in a washing machine and run the gentle spin cycle only.
- Without stretching the fabric, lay it out flat on a mat or on a couple of sweater drying racks [affiliate link]. Do not pin in place, but allow the fabric to find its size.
Ready to ship and custom knit fabrics are available in the shop now.
Last edit 20Nov2015 to update link.