Wednesday, March 20, 2013

How to Determine How Much Fiber to Spin for Your Project


(I suggest reading the previous article, "3 Tools to Make Your Spinning Better", before reading this one.....)

I've often heard spinners ask the question: how much fiber do I need to make X item? And the answer to that question is done by determining the GRIST of your completed yarn.

Grist is essentially, the mass of your fiber times the length of said fiber.

Grist = Length per Weight = L / W

In order to determine how much fiber you need for a given project, you need to create a finished sample skein in the yarn weight you want to achieve. (Unfortunately, there's no other way to determine how much fiber you need., so you need to spin up a sample skein.)

Once you have your sample skein, you can either use the equation above to determine the grist or you can use a McMorran Yarn Balance (which essentially determines grist). You can also use grist to determine how much yarn you have in an unknown /unmarked skein/cone of yarn.

Real World Example:

From my previous blog post on Spinning Tools, I wanted to knit an Old Shale Stole using the following fiber.

IMG_1327

The pattern calls for 1200-1400 yards in a DK weight. So, I created a small sample skein of DK weigh 2-ply yarn.
  • Weight of my sample skein = .75 ounces
  • Yardage of my sample skein = 63 yards
So, my Grist= L/W  = 63 yards / .75 ounces = 84 yards / ounce.
There are 16 ounces per pound, so my grist is 1344 yards per pound.


I need a yardage of 1200-1400 for the Old Shale Stole. Consequently, I would need a minimum of:

(1200 yards) / (84 yards/ounce) = ~14 ounces of fiber.

Unfortunately, I only bought 12 ounces of the fiber, which gives me:
(84  yards / oz) x 12 oz=  1008 yards

I'd be short ~200 yards for the minimum needed yardage. I would need to purchase  more of each fiber type. But at this point, I KNOW what I'm getting into.

Combined with the spinning tools as mentioned in the previous post, I can easily calculate my way into having enough fiber for the yarn that I want to create. And not be surprised after all my hard work that I've fallen short of my needed yardage.