This vest is knitted sideways in a single piece to produce a half-width vest. The openings are then finished with a crochet chain and you have a full sized vest from minimal yarn.
Suggested yarns are a DK or sport weight and a contrast yarn to crochet around the openings - this be either a color contrast or a different texture.
The finished size will fit 32" - 38" but Lucy does give instructions on how to make it both longer and wider.
There are 5 pattern pahes with diagrams and charts.