There aren't any rules for fabric selection fot B9P that I am aware of. I used some very small prints in mine. And I've seen some that used solids exclusively. I like my fabrics to "flow" into each other, but some like high contrast. It is totally up to you. I used 6 fabrics in my king sized quilt. I am on my iPod but you can find mine by checking out my topics. I called it "Blooming Lilacs". Good luck!