The incomplete to complete grain boundary (GB) wetting transition is controlled by GB energy and, therefore, by GB character. To find the GB character dependence of the wetting transition, experiments were carried out on polycrystalline Cu-In alloys, which are known to exhibit wetting behaviour between 715 and 986 A degrees C. Electron backscatter diffraction was applied to determine the two-dimensional GB character, using the coincidence site lattice (CSL) model and applying the Brandon criterion. Special wetting behaviour was found in those GBs characterised as low-angle, I 3 pound and I 11 pound. The low-angle and I 3 pound GBs were not wetted until the sample melted, while the temperature for the transition to complete wetting of I 11 pound GBs was over 100 A degrees C higher than that for complete wetting of all other types of GB, including other CSL GB as well as random GB. It might be that a different Brandon type criterion is needed in the case of GB wetting to show the "special" wetting behaviour of the CSL GBs.