Melt fraction of different mass planets at 1 AU during crystallisation, showing the variance in crystallisation lid regimes. The upper white horisontal line represents the lid thickness at which degassing is no longer efficient and volatiles start to be trapped in the mantle. The lower white line shows the core-man tie-boundary. The M = 0.5 M_⊕ planet has a short magma ocean cooling time-scale, resulting in bottom-up crystallisation without forming a lid. The other two planets first form a thin lid before also starting to solidify from the bottom. The planet with M= 2 M_⊕ planet solidifies slightly faster than the M = 4M_⊕ planet, which allows for more of the volatiles to be degassed through the thin lid before the lid grows thicker than our assumed limit for where degassing can occur.