You will need 5 buttons. Rowan used # A04TI from Groves & Banks in the UK.

Finished measurements:
Back: 14(15, 15.5, 17, 18)“ 35(36, 40, 43, 46) cm
Length: 16(17.5, 19.5, 21, 22)” 41(45, 50, 53, 56) cm
Sleeve length: 10(10.5, 13, 15,17)“ 25(29, 33, 38, 43) cm
Sleeve cap: 3(3.5, 3.5, 4)” 7(8, 8.5, 9.5, 10) cm

Yarn used:
Rowan Handknit Cotton
A. Ecru 251 3(4, 5, 5, 6) balls
B. Black 252( 3(4, 4, 5, 5) balls
C. Rosso 215 - 2 balls for each size
93, 36.5, 3.5, 4)“ 7(8, 8.5, 9.5, 10) cm