I sprayed some water on the wrinkles and toss in the dryer on low and was amazed. All the wrinkles Gone.

I use Wrinkle Release spray and put in dryer. The same way I get the wrinkles out of my cotton clothes.

Help. This suggestion may need. Someone to say if it would work. If you have tried to get them out as mentioned above. Damp and it on a line to dry outside. Let the wind blow it. Also when you finger tip the batting straight over the backing you will find some more come out as you do this gently.

I only use 100% cotton batting. Batting is heavy - i open the package up at the beginning of the piecing process to let it relax. I have some tall shelves in the basement and hang the batting from there and let the weight of the batting pull the wrinkles out. Probably works similarly to hanging it on a clothes line.