9" x 7" is real small. I have made them and they are about 1 1/2' x 10 - 12". I would measure one that you like the size and make it from that. Just a suggestion.
I agree that it needs to be bigger. Mine are 18" x 9".
I use 1 " strips of Christmas fabrics on an angle. They are easy and the kids like to find the different patterns-- almost I Spy.
