If I understand it, you increase 12 stitches on one row and then continue working for 11 inches in length, not width. That would be several more rows, depending on your needle and yarn size.
Seed stitch is knit, purl, knit, purl, doing the opposite on the other side so that the stitches end up looking like little seeds on the fabric. Both sides look the same with this stitch.
Seed stitch is knit, purl, knit, purl, doing the opposite on the other side so that the stitches end up looking like little seeds on the fabric. Both sides look the same with this stitch.