Apparently the deliberate imperfection myth is just that...a myth. I'm a quiltmaker and I read a lot about quiltmaking and quilt history, and it seems to be a story that has attached itself to Amish quitmaking. If someone making a quilt ran out of - say - dark blue fabric before finishing the quilt and substituted a lighter blue fabric for one or two blocks it was not a 'deliberate' mistake, just an attempt to finish something already started.
We need Rapaire in on this, his wife has a house full of quilt books!

Cheers
JennieG