i make lots of raggy quilts for throws/couch cuddle blankets...i always use batting- like them fluffy/lofty...generally a nice cotton batt- warm & natural, hobbs 80/20 (is a favorite). i've made a couple with flannel in the middle- they ragged ok- but were awfully - flat- i think the ones with layers of fabric- flannel, homespuns or regular cottons are heavier than ones with batting- which gives them a fluffy loft- a lightweight batting is less weight than yards of flannel-
just my thoughts.