A perfect jelly roll would be 40 strips with no doubles. All the fabrics would be bright cheerful 30's prints. And the fabric would feel wonderful. I do have a jelly roll with 30's prints, but she snuck some doubles in there and they are totally ugly !! I felt really cheated when I got home and opened them to check them out. Sure cost me a pretty penny for those ugly Men's underwear type fabrics (my Mother made me iron my stepfather's boxers in the 1960's).