Originally Posted by ckcowl

you will get lots of (personal opinions) about this--
i've made something like 27 flannel raggy quilts- i've never pre-washed the flannels for raggy quilts (i do pre-wash flannels for regular pieced quilts which are mixed with other cottons)
all of them have turned out great- they fray/rag nicely- and make wonderful fluffy, soft cozy quilts-
shrinkage amounts a dependant on a lot of factors besides (oh no its flannel)
the batting used (if used) the amount of quilting- the size of the blocks.
if the flannel is an inexpensive flannel-thin with a loose weave it will shrink more than one that is heavy- double sided- nice quality-
but i've never had shrinkage be a factor in the great outcome of a raggy quilt.
some people insist on pre-washing their flannels 2 or 3 times before using for anything---in my mind that is a huge waste of water- but to each their own.