When I started designing my own patterns and wanted to share them I realized I needed to know yardage requirements. Ack. I decided that the displacement technique was the best solution for partially used balls or non-commercially-prepared skeins where your mileage may vary. You know the drill, right? Measure the length in the ball, knit, and measure what's left.
I was aided in this exercise by a desk one of my carpenter grandfathers built from scraps during the Depression. (What are the odds that both my grandfathers were carpenters, and that I myself would grow up to be so interested in and yet incompetent with woodworking?) It's like he knew I'd one day need a table that is exactly 1 yard wide:
I like to work with yarn wound into a ball, tossing it into a giant Tupperware bowl so it can roll around as I draw off one yard at a time. We'll skip over the agony of measuring out fingering yarn that comes in an approximate yardage of 683 yards for a 100g ball, and note the convenience of a carpenter's measuring tape hooked over one end of the desk and stretched out to the other to make measuring the last few inches of yarn a simple matter.
You may be wondering what that B-shaped blob is on the upper right corner of the desk. Seen from this angle it reminds me of a superhero logo beamed onto the surface, but actually it's symbolic of the day I learned why a drippy nail polish remover bottle is never going to be best friends with finished wood.
For the intial measurement, I make a note of the length, but if I'm knitting with the yarn held double I'll slip each ball into a Ziploc bag marked with the length of that particular ball. In the 'after' measurement it's interesting to see how much more yardage one put into the project than the other... sort of like the outside edge of a race track versus the inside.
When I'm done knitting and measuring I like to tie a pretty label on to the end of the ball with the fiber and length marked, because I find it so much more fun to look into a drawer of possibilities than one of plastic bags.
And there you have it. Simple yet effective and
so time consuming and back-breaking!
If there's a better way, I'd love to hear about it. Really. Loooove to.