Recently, there was some polyester batting on sale at Joann's. I had used some medium loft polyester batting before and it came out nicely but this was a different brand on sale. I wasn't really thinking that perhaps not all battings are created equal so I bought some for my next three projects. :? The first project came out nice but after a few washings, it went flat. Now, I'm finishing the second quilt top and not sure what to do. I'd like to do the sandwiching today since I won't have any time in the next few weeks, but I also can't run to the nearest Joann's today...it's over 20 miles away. Should I take the last two of these battings and try to use them together, one on top of the other, to make it thicker or not?

You might find two thicknesses difficult to quilt through. Both machine and hand quilting are easier to do on thinner battings. If I were planning to layer these two battings and machine quilt, I would be tempted to add close-together machine basting lines with water-soluble thread to try to keep the thickness under control.