backing, batting, white fabric and scraps. place scraps on top and quilt as you go. (This was done on a longarm. Wondering how well it would work on a regular sewing machine.
The Girl Who Quilts: Scrappy Blocks Tutorial-Several other useful tutorials and tips-Love the magnetic pin bowl!
Speedy Scrappy Improv Quilt Blocks Tutorial and final pics of the quilt here.
rail fence variation 2 patch + 4 patch great breakdown of this block -quilting idea for rail fence, circles!