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.
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.