NLTE abundance corrections for representative lines of aluminium computed in a range of metallicities and LTE aluminium abundances for 1D MARCS models. The stellar parameters T_eff (in units of K) and log g (in cgs units) and the line central wavelength (in units of Å) are indicated in each panel. Overplotted isocontours indicate the reduced line strength, log W_λ/λ, in LTE (dashed lines) and NLTE (labeled solid lines). Each row presents results for a different line, and each column a different stellar model representing, from left to right, solar analogs, the main-sequence turnoff, the lower and the upper RGB.