Are you going to machine quilt or hand quilt it??
I am a cotton fan, but flannel will work.
Wash the flannel in hot water and machine dry before using as batting, it does shrink quite a bit.
The term is 'bearding' and battings have gotten much better controlling it, but I did have problems with a navy quilt years ago.
Rosa

Thank you Rosa- I plan to machine quilt it. I am not sold on using the flannel - I do like cotton - is there a really light weight cotton batting I should be looking for? Bearding...That's it! - I am glad you understood what I meant - you saved me from looking it up in one of my books I am accumulating.

There is a batting out there that is made for quilted wearables and table linens. It's called Thermore, I think, and it is quite thin, but will give your quilting more definition than just a piece of flannel.

Yes, I did a google search. It is called Thermore, and it is fairly widely available. It is polyester, but I think that's a good thing for such a thin batting. It will be dimensionaly stable.

I only use Warm & Natural (and in the past, Heirloom). These are both very thin cotton battings, either of which I think would work well for a runner.

I think anything that isn't 'high loft' would be fine...the more loft, the more quilting would be necessary to 'flatten' it down.

Can't wait to see pictures of your project!

Dang, I wish there was a spell-checker on this forum!! Dimensionally stable!

I also forgot to post the link:

Here is a link that might be useful: Google search: Thermore

This is a hand quilted table runner with cotton batting. It lays flat and cotton is easier to MQ, it hugs the material.

Rosa

I like Thermore the best but use Hobb heirloom 20/80 without a problem as well. Some of the polys seem to have more loft. I have never uses Warm and Natural but understand that it also works. Jayne

I like Thermore or cotton flannel for table runners because it lies very flat, but still looks like a "quilt." If I put a vase of flowers on it or a pretty bowl, I want it to sit as flat as possible. Both Thermore and the flannel are thinner than Warm & Natural or Hobb's Heirloom.
Teresa

And, you can buy flannel in a dark color to match the quilt so bearding wouldn't show.

There is also some dark batting made now, specifically to combat this problem. I don't recall its name but maybe have seen it in catalogues? It's either navy or drak grey/black if I recall?

I used Thermolam with good results. I found it at Walmarts in with the muslin and Pellon products.
Both of these were made with it.

Unfortunately, my quilting skills are lacking, but I love how thin this stuff is (about 1/8") and still shows the quilting. I don't recall seeing any bearding and somewhere on the below linked site, I did see something like this in black (but it may have been a fusible).
Cathy

Here is a link that might be useful: TP970 - Thermolam Plus

I use fleece that comes in a bolt and you buy in yardages. There are several thicknesses.

I don't think the Thermore or cotton flannel will beard on you. And other batting that is needled or scrimmed will not beard either. The bearding results over time when loose fibers migrate to the top of batting and begin to poke themselves through the quilt top - usually from lots of movement that a bed quilt would get from being used (and made up) everyday on a regular basis.

There are dark battings on the market, including wool battings, but they are bed quilt weight and are thicker than Thermore or flannel.

Thanks for all your responses & the links. I appreciate your guidance.
Cute runner Rosa - did you do the embroidery by hand as well? Very nice!
Cathy - I especially love the Irish (and "yum" green beer) placemat - I'm 100% Irish - added that on my To Do list.