8 x 9 blocks = 72 blocks = approx 96 x 108 inches
Using the suggested measurement of a 6x35 inch strip of each fabric for one 12-inch block -
(for 12 x 35 inches of total fabric per block )
(Assuming the 6-inch strips are cut parallel to the selvage and 6 strips cut per yard length)
I come up with 12 yards needed for EACH fabric. Which would be 24 yards. Which seems like an awful lot.
If one can cut seven 6-inch strips from the width of fabric, than it would take 11 yards of EACH fabric. 22 yards total. Which also seems like a lot.