Thanks to one of your for pointing out an error on my part in the kit for the Royal Iris. The pattern instructions say to cut a 30 inch square of background fabric (the light yellow) which works for the fabric requirement on the back. 30 inches is oversized by 5 inches.
However if you purchased the kit with hand dyed fabrics included it only contains 27 inches of the light yellow background fabric. Please cut a 27 inch square which will still give you 2 extra inches.