You will need 3 buttons, approximately 5/8” (15 mm). Rowan used brown wooden concave buttons #TGB4083 from Textile Garden in the UK.

You may wish to use a circular needle, working backwards and forwards in rows, not rounds.

Finished measurements:
Chest circumference: 32.5( 36.5, 40.25, 44.25, 48.25, 52.25, 56, 60, 64)“ 82.5( 92.5, 102.5, 112.5, 122.5, 132.5, 142.5, 152.5, 162.5) cm
Finished length: 18( 19, 19.75, 20.5, 21.25, 22, 22.5, 23.25, 23.5)” 46( 48, 50, 52, 54, 56, 57, 59, 60) cm

Yarn used:
Rowan Cotton Trio
Shade 120 Deep - 5( 5, 6, 7, 8, 8, 9, 10, 11) balls