Abstract: A light-triggered tattoo process. A strong absorber of light energy and tattoo material are sandwiched under pressure between a skin region and a transparent window. Short pulses of light, at frequencies strongly absorbed by the strong absorber, illuminates the strong absorber through the window creating micro-explosions in the strong absorber that drive particles of the tattoo material into the skin region producing a tattoo.

Abstract: A method of using a penetrating protective sealer to mark a message onto a porous surface is provided. Once the sealer has been applied to the surface and is allowed to dry, the message will not be visible. An indicator dye can be used to aid in application of the sealer; once the sealer has fully cured, the indicator dye is no longer visible. When the marked surface becomes wet, the portion of the surface that has been treated by the sealer will repel water; the remainder of the surface will absorb water and turn dark. The contrast in color created between the darker, untreated/wet, surface and the lighter, treated/dry, surface will result in a visible message to an observer. The message can be a warning or an advertisement. A thickened penetrating sealer composition and a method of using the same is provided. The thickened sealer results in neat, clean, crisp edges for the message.