Sew a Tunisian crochet seam - side edges top to bottom

Learn how to sew two side edges of Tunisian crochet. This technique will work with most Tunisian crochet stitches but the demonstration is using Tunisian simple stitch (tss). This technique is an adaptation of one shown in the Japanese book 'Basic of Tunisian crochet for beginners'. It's adapted because in the book the pieces are bottom up - the foundation row is at the bottom and you work your way up. In this method, you work from the top down to the foundation row which means the stitches face the opposite direction on both edges.