Summer quilts are so named because they are to be lightweight. No batting. But even so, they also have more fabric in them that the batting would not be needed. Classic example is cathedral windows. I made a origami quilt top. Lots of fabric, lots of folding. It does not need batting. Batting comes in different weights, so if you want to add batting you can. Batting also gives body to a quilt and helps it retain its shape. And the quilt will last longer.