At knitting group last week Cynthia brought in some laceweight yarn she found at the thrift shop. Three good-sized center-pull balls in a soft white yarn, more than enough to make a shawl. The yarn didn’t have any tags so there was no way to tell the content or yardage. I offered to see if I could figure out some more information.
Wool or acrylic?
The first thing was to determine if the yarn was wool or acrylic. It felt soft and pulled apart easily and I thought it might be wool. But I’m no expert so I decided to conduct a little experiment. It’s the kind I like — I got to play with fire!
The makeup of fabrics and yarns determines how they burn when they come in contact with flames. For instance, wool is self-extinguishing — it takes a lot to get wool to burn. Petroleum-based products like acrylics and nylon will melt and then burn. Plant based fibers like cotton and linen smell like burning paper. Knowing a little bit about these characteristics can help you ferret out the content of mystery yarn.
I snipped off a piece of the yarn and, for good measure also tested a piece of yarn that I know is 100% wool — the same Koigu I used for the baby booties. A tin pie plate and a couple of matches and I had my answer in about 15 seconds.
On the left you can see the Koigu. I laid the lit match on it and it immediately went out. I relit the match and it burned about half way before extinguishing itself. You can see the yarn charred but really didn’t burn. It’s a great reason to use wool for baby clothes. Or any clothes.
On the right, is what’s left of the mystery yarn.
As soon as the flame came in contact with it, it started to melt and then it fed the flames until both yarn and match were used up. It By the time the match had burned itself out, there wasn’t even a plastic nubbin left.
Definitely not wool. Definitely an acrylic of some sort. From the color of the flame, I’m guessing there’s some nylon in there as well as an acrylic of some sort.
If you want to learn more about the burn test and the characteristics of different fibers, you’ll be able to find a lot of sites by Goggling “fiber burn test” or some such. Here’s one site that I like.
Next was to figure out the yardage.
McMorran Balance
When I first started knitting I bought a McMorran balance because I thought I just couldn’t live without it. I haven’t used it all that much, but it does come in handy when I need to figure out yardage. Here’s how a McMorran balance works.
Set the counterweight so that it swings freely in the deep notches in the base. Snip a length of yarn and place it in the V-notch of the counterbalance. Be sure your yarn doesn’t rest on the table because it will skew the results. If the yarn is so fine that you need more than one length, double the yarn over or cut multiple short strands.
Keep adding strands until the arm is nearly balanced. Then start trimming the strands until the balance arm is horizontal.
Remove the yarn and measure it. In my case, I had multiple strands so I added up each strand’s length to come up with a total.
Multiply the final measurement by 100 and you’ll have the yardage per pound in ounces. In this case there would be 4300 yards in 16 ounces, or 268 yards per ounce.
Now, all I have to do is multiple the weight of each ball by 268 and I know the final yardage for Cynthia’s great find.
The whole process is so much simpler than explaining it. It took me longer to build this post than it did to do the burn test and the measuring. But both are useful skills/tools to have in your knitting arsenal.
