Multi-component slab model fits for the different methods of radial gradients: method 1 (radial temperature gradient, without overlapping regions) is shown in the top panel, whereas the methods 2 (radial gradients with overlapping regions, but no line shielding) and 3 (radial and vertical temperature gradients) are displayed in the middle and bottom panels, respectively. The full model is in each panel shown in green, whereas the components are coloured depending on the corresponding temperatures. Red indicates the hottest component, followed by the light blue and dark blue ones. The green horizontal bars indicate the regions used in the ${\chi }_{\text{red }}^2$-fits.