In my current mode of seeing things through to a finish, I added dark charcoal fabric to bring the back of my "map" quilt up to size. (Map quilt because the Westminster fabric used looks like contours.) Then I sandwiched it and then just got on with walking foot quilting. I had considered having it longarmed but this is one to sell or give away so the added expense is not justified As I had spray basted it I washed it after quilting and before trimming. I zigzagged round the outer edge first.
The back - I used up all the extra pieces and showcased the original fabric in the centre.