An inkjet printing method for forming openings to buried semiconductor layers of silicon solar cells is described. The method uses an overlying resist as a sacrificial layer onto which a plasticiser for the resist polymer is deposited in a programmed pattern using inkjet printing. At the locations where the plasticiser is printed, the resist becomes permeable to aqueous etching solutions making it possible to form openings in underlying dielectric or silicon layer(s). The formed openings can be used to create metal contacts to the buried silicon layers of the solar cell. The increased permeability can be reversed thus enabling a single resist layer to be used to form more than one set of openings. Existing masking methods, used in solar cell fabrication, form openings in the resist layer and therefore are not well-suited to cell designs requiring more than one set of metal contacting patterns for different silicon layers.