i have made many many flannel quilts...i love working with flannel....and i know some people here SCREAM daily...WASH FLANNEL FIRST...TWICE!!!! in the past 45 years of sewing I HAVE NEVER PRE-WASHED MY FLANNEL and i have never had anything i made with it not come out fine...when a flannel quilt is all done, pieced, quilted and bound then and only then does the flannel go into the wash...i wash it like i wash anything else, normal setting, warm water. then i toss them into a nice hot dryer...they come out FLUFFY- SOFT- OH SO COZY!!! one word of caution...empty the lint trap a couple times while drying...it fills up fast. and just go for it...there seem to be some people who search and search for things to be (indignant about) pre-washing is one of those 'hot-topics' but it all boils down to personal choice and experience...you can not learn if you do not try.
3/4 flannel - 1/4 regular cottons...no-pre-washing done...washed before picture