Welcome travelinggramma. The minimum should be 12.5. Add a border on the 9.5 sides if you want. What kind of center are you thinking about?
I decided that my center is going to be a panel with 4 dolphins. It is in blues, navy, aqua and a touch of gold.
Our group likes to talk a lot and we love pictures. We still have not heard from Anne. Please post when you send and receive a center. Please share ideas and thoughts.