OOOOOhhhh! By thick, you mean the circle is like a donut with the center out....Ok, so once you cut the circle out and then the center out of that, you applique it on. That means you sew it on the top of what the quilt top. You could fuse it with steam a seam II and the do a zig-zag stitch around the edge to hold it down. Check out YouTube for some visuals on applique or raw edge applique. Wish I could show you, I am sure you could do it. Good luck. If there is anything else I can do I will try.