I'm taking the BOM from Craftsy classes and one month we did string quilts. We didn't cut on the bias. We did two blocks. One we had backing, and the second we had backing just so we knew how long to make our pieces, but we didn't use the backing...we cut it away after we sewed our string block together. I liked that method better because the block was thinner. But, like I said, we weren't using bias fabric. Anyway, why do you use bias fabric for string quilts? Wouldn't it be easier to cut on the grain? Am I missing something?