A friend gave me "many" 4-1/2" squares of baby print flannel and also the backing for the quilts. What size seam allowance also open the seams or press same as with other fabrics? What size for these quilts? My first time using flannel.........Fabric has been washed and pressed.
Any suggestions would be appreciated.

I always use 1/2 inch seams for flannel.

i use the width of foot, which is slightly wider than 1/4.

I like to stitch my seams at least 3/8" wide as flannel will pull away from the stitched line if the seam is too narrow. I also like to machine quilt baby flannel quilts as it stands up better than tying. I press my seams to one side unless it is extra thick at an intersection and then I'll press it open.

i would use width of foot unless flannel is thin then 1/2 inch

I would not press the seams open. If you are using simple squares, then you can press each row to the side so the next row will nest the seams. That gives you no chance for seams to pull apart orbatting to work through the seams.

Not sure about the seam allowance.

I have no problem using 1/4 inch as long as I make sure my seams are straight & true.

I use quarter inch on flannel, too. It has not been a problem.

I am doing my second flannel quilt that is not a rag quilt and was curious too how to press seams and what the best seam allowance is; I'll be watching this thread because you are all "in the know"!

I use a 1/4 inch seam but make sure that I use a smaller stitch. I have not had a problem with fraying. I always wash and 'hot' dry my flannelettes before cutting and piecing. I press the seams any way that will reduce bulk.