With the aim of realizing an easy and inexpensive method of realizing a “stealth” dot pattern, whose presence on a medium surface is not visually recognizable, merely through minor improvements in the existing printing technology, the present invention provides dots which form a dot pattern by printing these dots using an ink of any color reactive in the infrared or ultraviolet wavelength range on a medium surface on which a dot pattern is to be formed, for use with a dot pattern reading system that irradiates infrared or ultraviolet light on a medium surface having a dot pattern provided thereon, recognizes the dot pattern by reading the reflections of the light with an optical reading means, converts the dot pattern into the corresponding data, and outputs the text, voice, images and so forth contained in the data.