Double batting question
 

If I were to double my batting, would spray basting still work for all those layers?

Depends I find on the batting. Polyester not too well. Warm and soft much better.

I didn't use double batting but I did use Warm and Natural plus an extra layer of flannel on a double-size quilt. It worked fine. Of course, it was more time consuming and used more spray, but not significantly. However, next time I will use wool batting to get the extra warmth.

It should work. I would use 505, as it seems to work better for me than other brands of basting spray (especially on polyester, if that's what you would be working with).