A process of printing applies printing ink to the surface of a product of thermoplastic rubber compounds containing upwards of 95% mineral oil. The process uses ink compositions of resins, mineral oil, solvents, colorants, and additives. The process involves preparing a product from copolymer resins and other components, and blending an ink from copolymer resins and other components. Next, the process prints the desired multi-color image on the treated surface followed with a top coat on the surface of the substrate to protect the printed image. The top coat and ink stretch with the product so that the image remains intact. The process uses pad printing to print the image upon the surface of the product.