Thanks to Sue Ellen for this Frugal Baby Tip!
The best diaper flannel I've found is at Elizabeth Lee Designs online at http://www.elizabethlee.com . I just bought a whole bolt of it for $60.00!! I ordered it on a Monday and got it Wednesday ... fast shipping. I ordered Cathy's Back to Basics Pattern today and will be anxiously awaiting my mailman's arrival for days!!
Other than that, Walmart actually carries a Diaper Flannel 27"wide white fabric. Superflannel would also work and provides cute colors. DO NOT make your diaper entirely in regular flannel!!!!!! I made that mistake and my diapers fell apart within 2 months. What a waste of time and money. Make sure your flannel is a good solid quality.
Another option that I've found to work well is going "fabric shopping" in your own home. My two favorite diapers were made from items I just had laying around.
One is of a really cute receiving blanket and the other is of a tight weave peach linen tablecloth. The tablecloth diaper actually absorbs better than any other diaper I have!! LOL! Daddy's flannel shirt would make a really cute dipe as well.
Have fun sewing your dipes!!