I am doing a double reversible Table Runner. In my book
My First Quilt Book by Carol Doak it says for a table runner you put a layer of batting and a layer of muslin and then baste together. I made two sides of different fabrics so it can be used for fall and Christmas. If I did this I would have 5 layers. this is a pattern I bought but added extra blocks to this on runner for my girlfriedns table.

I am trying to finish it so I can get in the mail but after Christmas is ok.
I have 4 others but they are for next year. I am doing this to learn to read instruction & sew together, so I can make quilts.

I sent you a PM.

The only time I would use an extra layer of fabric is if the batting is too thin. I wouldn't think it would be necessary in this case :D:D:D

I think you could leave the muslin out of your "sandwich." Just put the batting in between the two tops.

I would think you could eliminate the muslin if you have batting in there. That's enough layers for a runner or a placemat.