Know Your Yarn: What Fiber Content Means for You

The type of fiber you choose for your knitting affects every aspect of your creation: your creation's physical characteristics, such as warmth and appearance, are all dependent on its fiber content. In addition, choosing your yarn wisely allows you to avoid actual or potential allergens, make weather appropriate garments, and keep the heirloom sweaters out of the washer and drier.

First, let's review the factors you should look at when picking out yarn for a project.

1) Washability. If you're knitting for children or others who prefer that everything be washer and drier safe, you don't want to pick an animal fiber which will be felt when exposed to hot water and agitation. (Not all animal fibers fall into this category: superwash wools and some blends are safe. Check your yarn's label to be sure.) On the other hand, if you are knitting a project which involves felting, you'll want to stick animal fibers which will felt.

2) Blockability. Blocking, the act of dampening and pinning out your knitting so that it assumes a desired shape or openness (in lace knitting), is important to achieving a polished, finished look. Lace, particularly, should not be knitted in yarn which does not block well.

3) Softness. Many wools and mohair can be itchy, and cause skin irritation. For clothes worn close to the body, you should select a fiber like merino wool, alpaca, or cotton which is gentle on skin.

4) Warmth. A cotton sweater isn't the best for heavy winter, just as an alpaca vest in the midst of high summer should be avoided at all costs.

5) Drape. Cotton and linen are much heavier and less lofty than animal or man-made fibers. Where wool is springy, cotton will stretch out and lay flat. Correspondingly, a cotton garment is often much heavier than a wool garment, which you should consider before trying, say, a cotton sweater coat.

Now that you understand all the factors that go into choosing a yarn, let's look at the most common fibers in commercial yarns today.