A stain is the evidence of something that was. It's a trace. A stain may be something quite ordinary: the ink stain on my index finger; the mark of your fingers on this book. A stain may also be embarrassing: lipstick on a cheek; sweat rings under the arms; a bloody discharge. A stain may be forensically incriminating. A stain may be kept for sentimental reasons. Moreover, every stain has its own particular texture. Texture denotes the consistency of a surface and the sensory, often tactile imprint that is left on it. The stain may be absorbed in the thing that supports it; then again, it may stay on the surface, something separate. Every stain is unique. In this essay the author deals with seven factors that make the stain into a powerful model for rethinking the visual: the stain as prototype and prefiguration, the stain as relic, the stain of Veronica, the stain as a psycho-energetic symptom, the stain as pars pro toto for the womb, the stain and le desir mimetique and finally the stain as an image paradigm of the residue.