I thought I should be quantitative as well as qualitative about my 30's bin bust project. I weighed the stash: 27 pounds. At 4 yards per pound, that's 108 yards. The weighing came after I completed the Pentland Crackers flimsy which used 3-3/8 yds of 30's (and 5-1/8 yds in all).
One shelf, two boxes. (The stack to the immediate left of the boxes is not 30's.)