Do you let the batting relax after taking it out of the bag, or if you buy yardage, do you spread it out and let it sit a day or two? Here's how I put quilts and runners together: I have a new king sized flat sheet that I lay flat over 3 lined up rectangle tables. Pulling each corner taut, I secure the corners to the table legs by wrapping them with cording. Then, when I am laying out the quilt, I lay out each layer, pinning along all edges of the quilt to the sheet. As I add a layer, I am constantly smoothing out from the center toward the edges. Then, I remove the pin from the previous layer and re-pin to the sheet, including the newly added top layer each time. Once all layers are together, I add several quilting safety pins throughout the quilt. I remove the pins from the sheet attached to the table, and then place thin slats along the edges of the quilt and clamp the table and the slat. I leave it sit for a day or two. As long as I place many quilt safety pins throughout the quilt, I dont have a problem with puckering. And letting the batting rest I haven't noticed any wrinkling in between the backing and quilt top. Doing all this may sound like work, but I cannot put together a quilt on the floor anymore as I don't want to depend on my DH to come give me a hand to get up again...achy hip joints and muscles. I hope you find a solution that works for you-good luck!