Most of the small size variations in these squares are of no consequence to this design. Once the edgings are on and everything is joined together, it all works out fine and the small size variations disappear. Just FYI– my square #15 is an inch wider than the others and I used it in my afghan anyway, so when you see my finished afghan you’ll be able to see that the size difference is not discernable in final result. However, I wanted to give you a heads up to the size difference in case you wanted to use a smaller hook.
Row 1: Ch 32, sc in second ch from hook, (skip next 2 ch, 5 dc in next ch–shell made, skip next 2 ch, sc in next ch), across, turn.
Row 2: Ch 3, 2 dc in same st, (sc in center dc of first shell, 5 dc in next sc) across ending with 3 dc in last sc, turn.
Row 3: Ch 1, sc in first dc, (5 dc in next sc, sc in center dc of next shell) across ending with sc in last dc, turn.
Rows 4-16 or until piece is square, or almost square: Repeat rows 2-3.
At end of last row, fasten off.
To make this stitch pattern any size, begin with ch multiple of 6 plus 2.