You can use traditional batting in your rag quilts if you like, but the instructions for that method are slightly different. I recommend you use a cotton or mostly cotton batting, making sure it's a type that doesn't require close quilting stitches. Cut the batting so that it's a little smaller than the finished size of the top and backing pieces. For example, our 10-inch squares finish at 9-inches since we're using a 1/2" seam allowance on each side of each piece. Cut batting pieces that are about 8-1/2" square and sandwich them between your top and backing. The extra half-inch we're shaving off the square gives you a little more flexibility when centering the batting, because you don't want it to end up within the seam allowance.
Secure the packet with straight pins and machine sew a diagonal seam from one corner of the square to the opposite corner. Repeat to sew along the other diagonal, creating an "X" with quilting stitches.
The "X" isn't mandatory -- it's just fast. You can do other types of quilting. Read your batting label to find out how closely stitches should be placed. One more thing, avoid placing lots of quilting in the seam allowances, because you want those areas to be as stitch free as possible to encourage fraying.
