I just heard a saying on batting about
"show the dimples and hide the pimples".... I think it was on Fons & Porter but I'm not sure.
What she meant was have the bumps (pimples) pointed towards the backing...away from the needle going in and out.
Show the dimples (indentations) since that is the way the batting was made and it works best for it to be next to the top.
Here's an article too:
http://www.apqs.com/blog/2013/01/22/...n-up-and-down/