Note: This is not part of the 12 Block Series, but one I hope you like anyways!
Chain 31, turn.
Row 1: Work sc in second chain from hook and in teach chain across. Ch 1, turn. (30 sc)
Rows 2: Sc in back-loop only (BLO) of each stitch across. Ch 1, turn.
Repeat Row 2 until desired length. At the end of the last row, do not ch 1, do not turn.
Border/Edging: Work three sl st into the corner (and in each of the other three corners). Work sl st evenly around the block.
As always, feel free to post any question or comment here, and I'll do all I can to assist!