Standard Gauge Single Bed Machine Knit pattern
This vest is super lightweight, and you can adjust the seam to have the piece either more/less open at the sides.
Pattern is suitable for a strong beginner/intermediate knitter.
I have written the pattern using terms related to brother single bed knitting machines - however this should translate onto other makes/models.

Knitted using 2ply yarn using a folded hem and partial knitting method. The pattern creates a front and back panel which is then seamed either using a mattress stick or using a linker if available.

The finished vest measurements:
26” top to bottom
19” pit to pit
15” shoulder to shoulder