shrinkage
I have measured hundreds of pieces of fabric before and after washing them.
I started to measure after I noticed some cat print fabrics that I wanted to sell were measuring less than 36 inches long - and I knew that I had purchased yard cuts!!!
from my experience with 100% cottons that would generally be considered "'quality' quilting cottons"
1) some do not shrink at all (very few)
2) the majority seemed to shrink more lengthwise OR crosswise ( i have noted up to three inches crosswise)
3) a few shrank equally in both directions
4) maybe one in a hundred increased a bit in size
the most shrinkage I have seen was where a 5x5 charm reduced to a 4.5x5 charm.
some of the more expensive lines shrank just as much or more than some of the less expensive lines