I followed the directions to make a bundle and put it a flat rate Priority Mail box and it is ready to go... Solids and large pieces were suggested so I just happened to have almost 15 yards of a lightweight burgundy twill (a slipcover that never was!) to send. I had room to add a few other smaller pieces of fabric, some burgundy thread and assorted ribbons.
Considering sharing your stash - follow the links to the info & directions to make your own IBOL.