I like to use the Essex cotton/linen blend by Robert Kaufman as the off-set blocks because they give some added texture and contrast to the quilt. (You can find it here, and here.) Not to mention when the quilt is washed, the linen shrinks and crinkles up so nicely, giving the quilt a nice vintage feel. I have a simple pattern for this i-spy quilt in my etsy shop.
I had the perfect backing in my stash – a Moda print by Jan Figuroa from a few years ago with more items to spy! The quilting is a simple meander loop by Melissa of Sew Shabby Quilting.