Finished the fourth binding, and musing on the material requirements of quilting

I just finished putting in the final stitches on the label of the fourth quilt.  It boggles the mind how much sewing goes into a large bed quilt.  On binding alone, in the four I finished there was just shy of 1600 inches of blind hemming!  Astounding. 

And the fabric!  There is about 7 1/2 yard on each backing of these big quilts including margins, and anywhere upwards from 9 yards in a quilt top.  The seams eat up a huge amount, as I discovered when I totaled what went into one of them.  For example, the 100 inch square log cabin quilt I just finished had 64 10" square blocks, and two borders, the first 2" and the second 8".  Each 10" block is 100 square inches but requires 162.5 square inches of fabric.  That's 10,400 square inches for the blocks, 825 square inches for the first border and 3,400 square inches for the outer  border, for a total of 14,625 square inches of fabric.  Using an average usable width of 42" for a bolt of quilting cotton, that's over 9 1/2 yards of fabric and these were simple blocks without a lot of seams.

No wonder quilting is getting so expensive!