It uses up every scrap of yarn; being knit side to side you divide your yarn into 3 equal sections by weight so that you can knit until it has (almost!) all gone. As an added bonus this means that it give a really wearable length from the minimum of yarn.
Yarn and yardage requirements:
I used: Luxury yarns Angelo lace in Happiness (600m)
You could substitute any lace yarn in a majority natural fibre. Test knitters also made fingering weight versions.
Construction, instructions and techniques
Just knit and yo sts are used for most of the shawl with one special knit manoeuvre on some rows of the border. Knit side to side so you never have a huge number of sts on the needle.
Full written and charted instructions for knitting the shawl. Full written description of how to block the finished piece.