I'm getting ready to sandwich the baby quilt for my niece. I've decided to use sage green flannel for the back and the striped fabric for the binding. I need help deciding about batting. I'm machine quilting it, simple SID. I may be over-thinking this, but I can't decide whether to use a. warm 'n natural batting with the flannel or b. two layers of flannel or c. just one layer of flannel with no batting. I'm most concerned with the technical aspects of making it work (preventing shifting, excessive shrinking, etc...). All the fabric was prewashed before the top was constructed and the flannel was prewashed once also. I'm inexperienced and would really appreciate some input so I don't make a stupid decision at this point!
Love this quilt!
I highly recommend that you heavily starch the backing before layering, especially since it is flannel. Heavy starching will stabilize the fabric so you don't get puckers when you machine quilt. My method is to mix a 1:1 solution of Sta-Flo liquid laundry starch and water, "paint" the solution on the yardage with a large wallpainting brush until the fabric is saturated, toss in dryer, then iron with steam. The backing fabric will not stretch or move on you while you are quilting.
It's also a good idea to heavily spray starch the top, for the same reason, to stabilize so the fabrics don't distort on you while you are machine quilting.
Your choice of batting depends a lot on how apart you are going to make your quilting lines.
My favorite machine batting is Mountain Mist Blue Ribbon 100% cotton. This is a thin, antique-like batting that creates a crinkle effect when washed. One of the reasons I love it is because it gets softer with every washing. However, this is a thinner batting than some people like, and it needs to be quilted every 2 or 3 inches.
Hobbs 80/20 is my second-favorite batting. Gives a little more puff but still easy to handle. (High cotton content means the batting will cling to your fabrics to prevent shifting; all polyester battings are much more likely to slip and slide a little.)
Many here like Warm & Natural, which is an extremely stable batting needlepunched through scrim and therefore can be quilted up to 8 or 10" apart. However, the scrim creates a slightly stiffer drape than the two battings I mentioned above, which is why I prefer not to use it. It is also heavier in weight than the battings above. Some people like weight, but I do not.
I use a single thickness of flanel as batting in my flanel quilts. The result is very supple quilt. I buy a good, but not LQS quality white or ivory flanel by the bolt and keep it on hand.
My favorite batting for baby quilts is Quilters Dream Poly. It is absolutely gorgeous quilted up, and it takes a beating and keeps on going... important for baby quilts.
I also love flannel backs for baby quilts.