Originally Posted by
true4uca
I sometimes will cut my backing into four pieces and in your case do a ten inch cross . HTH.
I do the same if I need width and length. I'll run coordinating fabrics both up and down in a plus sign. But I don't try to center them, I off center them. That way if it gets crooked, it was intentional. If I only need width, I'll add any extra blocks to the width and make it wider.