A shadow or ghost is the light colored remnant of a graffiti tag. It is comprised of paint pigment that remains after the paint carrier has been removed and usually all the pigment goes with it. Shadow Max® is designed as a second step -- not for use as a first step on porous surfaces, only to remove leftover pigment. For extra punch, after initial removal efforts, apply a spray coat of Shadow Max followed immediately by an application of Elephant Snot® -- let stand for five minutes, then pressure wash.