This is a very old, classic pattern. It's 2.5" squares that are sewn together to make a 6.5" unfinished 9-patch. The "snowballs" are 6.5" squares that have 2.5" white squares laid on each corner and sewn diagonally. You cut off the excess fabric and it makes each square have white corners. You sew the 6.5" snowballs alternately with the 9-patches, and viola! 6" finished blocks, and make as many as you need. This is a lap quilt for a tiny lady, so it's not all that big.