Colour-magnitude diagram of M_J vs J − K showing the observed low- and planetary-mass objects of the ESO SupJup Survey. The companions and their hosts are pictured as black hexagons and diamonds, respectively. All 19 observed isolated BDs are marked as black-outlined circles, and the colour denotes their spectral type. The same colour coding is used for the population of isolated cool dwarfs indicated in the background. These objects, originating from the UltracoolSheet (Best et al. 2024), are shown as a reference.