What happens if you purl every row?
If you purl every row then you’ll end up with garter stitch. If this sounds crazy, think about it: Traditionally, garter stitch is done by knitting every row. A purl stitch is also a knit stitch.
Does seed stitch use more yarn?
Yarn Consumption: Though the constant alternating between knit and purl stitches produces a slightly tighter fabric than stockinette, seed stitch does not use significantly more yarn. … It is not suited for variegated yarns or other colorwork, as the subtle patterning is lost in the color changes.