J, J − K_s colour–magnitude diagrams of the Quintuplet outer fields. Proper motion members are shown in green, while non-members are shown in red. Disc and Wolf-Rayet candidates are also marked. The diagonal overdensity at J ~ 20 mag marks the onset of the red clump. The dotted lines mark the K_s = 17.5 mag boundary for proper motion member selection. The horizontal dashed line indicates the J = 22 mag limit, above which the combined cluster disc fractions are derived. The main-sequence selection is indicated by vertical dashed lines. The variation in main-sequence colour between fields is caused by the locally varying extinction across the cluster area. The J, J − K_s diagram of the central Quintuplet field is shown in Fig. 16.