Thank you all so much for your replies and links! So much knowledge here I love it. I just started cutting my circles this weekend... ended up being 6-1/4"... now I can't decide what size for the "window" I am bouncing between 4-1/2" and 4-1/4".. not much difference I know. It appears when I cut my circles I wasn't perfect.. they very close but maybe 1/16" on the plus side and 1/16" on the short side. I have a template for 4-1/2" so that would be easier, when I go to 4-1/4" I worry about getting the "window" material centered correctly......maybe I am just being to particular and 1/4" won't make a difference either way. Any thoughts?