What is the best batting to put on a table runner so after it is washed it still lays nice?
Pickle

Will be watching the anwser to this question

We use Therm More. Not sure of the spelling, but it is a thin polyester batting.

I use old flannel sheets instead of batting--
Unless you want to say bad words, starch it well and iron!
Most batting is just too fluffy and besides, the flannel sheets are about $1-2 at garage sales or thrift stores!

I like a flat table runner, so there are no wobbles when you set stuff on it, so I use Warm and Natural. No wobbles.

I usually use Warm and Natural for table runners, placemats etc. unless I want them flatter. I have done placemats with just muslim inside.

This sounds good to me I also thought about iron on interfacing just for a little body.I like the muslin idea.
Pickle

What a great idea....Haven't made a runner yet...I'll try this.

Most of the time I use flannelette ... just enough body, but not too much. Easy to quilt.

Warm and Natural is nice for more body/thickness. I hesitate using it if I'm going to be setting something finer (eg. water glasses or stemware) on it as it may not provide for stability.

Or if you have some ugly fabric or some you will never use, what about hiding a layer or two of it inside?

Those are really good ideas, I never thought about whether you are going to be putting something on them that might tip over.

I usually just use Quilter's Dream or something like that.