I'm going to use the same method (using a different fabric as a stabilizer & birthing the circle) on my batik strip quilt, too. I wanted a nice clean edge, and feel the extra bit of fabric on each circle is going to make it stand out just a tiny bit more again the batik strips, besides being easier to applique onto the quilt top....I am probably going to add a small piece of batting, too, so that the quilting on those circles adds a bit to the quilt top in texture and interest.