A method of making a lithographic printing master is disclosed which comprises the steps of providing an imaging material which comprises a lithographic base having a hydrophilic surface and a non-ablative image-recording layer which is removable in a single-fluid ink or can be rendered removable in a single-fluid ink by exposure to heat or light; image-wise exposing the image-recording layer to heat or light; processing the material by supplying to the image-recording layer a single-fluid ink which is an emulsion of an ink phase and a non-aqueous polar phase. The use of single-fluid ink as processing liquid is a simple, convenient method for the on-press processing of the above defined material.