I agree about not buying Roc-Lon. I'm current doing a CW using 108" wide 15 yard bolt of Roc-Lon. It's quite flimsey. I'll probably turn this piece into curtains instead of a quilt. Lesson learned.
A queen CW quilt calls for roughly 25 yards of 44" wide fabric for the body of the quilt. I'm going by Eddie's tute. I'm cutting the muslin pieces 8.75" and the 'glass' pieces 2.5". 2.5" on the small pieces is a smidgen too big so next time I cut a batch, I'll cut them 2.25".