So I have this fractal spun yarn that isn’t totally my color. It turned out a little too pink for my taste but I can still use it. But what do I want to use it for? Well that’s when I realized I needed to know how much yarn I had.
Turns out I never measured it when I was making the skein. In my quest to go through patterns and not have to officially measure I ran into a conundrum. Not all yarns are the same so googling “how many yards in ounces” doesn’t mean anything. Well luckily I hadn’t wound it into balls yet so I was able to get a rough estimation but counting each strand in the circle.
Later that evening I pulled out my Alden Amos Big Book of Handspinning, and coincidentally I was on the chapter about Grist. To my amazement it solved the very issue I had earlier that day. This book is thee book for hand spinning!
As Alden puts it Grist is the relationship between Length and Weight, with a unit of yards per pound (you can also do metric if you prefer m/kg). He discusses this in detail but the part that I want to share is how to find out grist and subsequently the length of your yarn. This uses a bit of Algebra but is amazingly awesome!
If grist is length/weight and we know the weight then we can multiple the two and they cancel to give us the length. However, it isn’t that easy because there is something else we are missing, thickness or diameter of the yarn. If you can have two different yarns weighing the same but one is bulky and the other is fingering the length will be very different.
This is when we are introduced to Wraps per inch. Using an inch gauge one can wrap the yarn around it to find out how many strand of yarn can fit within 1″, this gives you diameter. And the last thing we need to compensate for is air and moisture within the yarn, that is our factor.
Grist equals Diameter squared times the Factor.
Alden Amos states that for medium firm woolens a factor of 0.87 works, and for firm worsted a factor of 0.90 works. The factor is annoying but it will get you to a good estimate of your yardage. Because once you know grist you can multiply that number by the weight and you know the length.
Grist times Weight equals Length
Since this is an estimation I would definitely under estimate it if I had a large project. And if you need to be precise look up the McMorran Yarn Balance. My understanding is it is best used if selling yarns and also if you want to measure art yarns or unusual yarns for length.
P.S. In tooling around the internet I found another website that discusses Grist and she uses in a way I didn’t know of but I love it! She writes about twist or wraps per inch which I didn’t cover but is in the Alden Amos Book. And she uses grist and wpi to calculate how much fleece she needs for a project. Super smart! Check it out: WelfordPurls