A method of printing on the sandpaper face of a nail grinding pad comprises printing, with an inkjet plotter printer onto a sandpaper surface, an ink composition including: 60% to 80% by weight of a polymer selected from the group consisting of: polypropylene glycol and its derivatives whose minimum molecular weight is around 200; polysaccharide and its derivatives; polyvinyl alcohol and its derivatives whose average molecular weight is around 10,000 to 200,000; polysucrose and its derivatives whose average molecular weight is around 40,000 to 400,000; and epoxy glycerol propoxylated glycerol and their derivatives whose average molecular weight is 500 to 10,000; and 2% to 10% by weight of a solvent dye or a pigment; 1% to 5% by weight percent of ethanol; and 0.1% to 1.0% by weight percent of surfactants.