Dependence of the open cluster’s total multiplicity fraction of systems with q > 0.6 on metallicity (taken from Recio-Blanco et al. 2023). The 23 OCs with more than three individual GSP-Spec [M/H] measurements in Gaia DR3 are highlighted as big orange circles with errorbars. The dashed red line is the running median for the 87 OCs in our sample for which GSP-Spec metallicities are available and the errorbars are calculated as the 16th and 84th percentiles.