One of the times I did not wash the fabric before making something out of it - ("pillowcases" for couch cushions) - they were nice and roomy when I made them - and I've ONLY washed them on tepid or cool water since - now I need to cram the cushions back in them. And that's when they are still damp. I'm guessing there was at least 2 inches WOF shrinkage in that piece.
Yes, I've noticed that many fabrics seem to shrink more in one direction than the other.