Visualisation of our light-curve correction and calibration procedure. For clarity, all light curves are plotted as consecutive points and not according to their actual time stamps. Top panel: extracted raw light curve of a target object (green open circles) in the gSDSS filter. The star used in this example is JVAR 113038.70+241022.56 (J-PLUS ID: 84850-294) from the field 00366. The vertical dotted grey lines indicate the different epochs of observation; the two wider blocks correspond to HFO. The horizontal solid green line corresponds to the reference J-PLUS flux for this object. Middle left panel: ensemble of comparison stars selected for this target (red points). Their light curves have been normalised by their respective J-PLUS reference fluxes. The solid blue line is the master correction curve obtained. Middle right panel: family of the 500 correction curves obtained from a bootstrap process, used to assign errors on the master correction curve. Bottom panel: raw light curve (open circles) and final light curve (filled circles) obtained after applying the master correction curve.