A marked article of manufacture created by means of additive manufacturing using one or more taggants deposited in layers, the article of manufacture being printed using a 3D printer and adapted to spectroscopically determine article authenticity, the article of manufacture comprising: a body of first material amassed by means of additive manufacturing, said body of first material providing a shaped structure upon which layers may be put into place; a patch of second material (3, 7) put into place by means of additive manufacturing at a respective predetermined location on the body of first material, said patch of second material (3, 7) having a thickness and an area, the first material and the second material (3,7) each having a spectral pattern employing a different chemical or combination of chemicals to alter the formulation of all or some portion of the article, said first material and said patch of second material (3, 7) being spectroscopically active when stimulated by a respective electromagnetic stimulation; a patch of third material put into place by means of additive manufacturing, the patch of third material covering the patch of second material (3, 7), said patch of third material having a thickness, said patch of third material at least somewhat transparent to the spectroscopic activity of the patch of second material (3, 7), wherein the article comprises at least two materials that look, to the human's eye, to be the same color, and which can be analyzed in the field with a chemical analysis device to ascertain whether a spectral pattern of the first material differs from a spectral pattern of the second material (3, 7), a difference in spectral patterns being an indicator with respect to counterfeiting a body of first material amassed by means of additive manufacturing, said body of first material providing a shaped structure upon which layers may be put into place; a patch of second material (3, 7) put into place by means of additive manufacturing at a respective predetermined location on the body of first material, said patch of second material (3, 7) having a thickness and an area, the first material and the second material (3,7) each having a spectral pattern employing a different chemical or combination of chemicals to alter the formulation of all or some portion of the article, said first material and said patch of second material (3, 7) being spectroscopically active when stimulated by a respective electromagnetic stimulation; a patch of third material put into place by means of additive manufacturing, the patch of third material covering the patch of second material (3, 7), said patch of third material having a thickness, said patch of third material at least somewhat transparent to the spectroscopic activity of the patch of second material (3, 7), wherein the article comprises at least two materials that look, to the human's eye, to be the same color, and which can be analyzed in the field with a chemical analysis device to ascertain whether a spectral pattern of the first material differs from a spectral pattern of the second material (3, 7), a difference in spectral patterns being an indicator with respect to counterfeiting