In the area of forensic sciences, the questioned document examination is one of its most attractive sections. As attractive as philately, the collecting of postal effects, in the modern world. Diffuse reflectance spectroscopy, due to have as main characteristic being a technique of non-destructive and easy to use, can be a tool of great value to the study of the philatelic pieces authenticity. In this work, using Diffuse Reflectance Spectroscopy, we present qualitative analysis of several early Spanish stamps issued from different emissions since the reign of Queen Isabel II to King Alfonso XIII, deepening over the series of the Provisional Government issued in 1870 - characterized by the profusion of variations of the colors found among the 13 values that compose the complete series-, and even studying authentic effects against other counterfeit recognized as fake copies.... [Leer más...]