I often have problems with measuring, and thought that someone here probably has a great trick for doing this.
I am somewhere close to the point on the back of a sweater where I need to decrease for the arm holes. I am using size 10.5 circulars for this sweater, and a bulky weight yarn. The pattern is a 4x3 rib, if that matters. The circulars are new and still are pretty curly. When I lay my knitting flat to measure it, I’m getting measurements anywhere from 14" to 15.5", depending on what surface I lay my knitting on (a flat but fabric-covered surface, a flat but slippery surface (like the pattern book), etc.), and whether I measure on the outside edge of the knitting or somewhere in the middle of the knitted part. Since 15.5" is where I’m supposed to start the decreases, I sort of need to figure this out. What is the best way to measure your knitting?