The circles are a little over 9 1/2 inches before sewing together. Then you have to draw rectangles on the inside and make a slit in one of the wings that later will be hidden under the folded flap. Then spray baste rectangles of batting and "glue" them to one of the circles taking the slit into account. Yes, I could imagine that 4 inch circles would be challening. this was a once in a life time for me. LOL