Spectroscopy has long been a popular subject with respect to postal stamps, but analysis of postal stamps has been the subject of only a few spectroscopic studies. Fourier transform infrared techniques were used in developing a nondestructive technique to analyze the adhesives on the back of stamps. This factor is of importance since the value of a stamp is partially dependent on the conditions of the original adhesive. Diffuse reflectance was finally settled on as the method of choice for this analysis, and it shows great promise not only for stamp analysis but also for other types of documentation analysis as well.
Matthew Poslusny and Kenneth E. Daugherty, "Nondestructive Adhesive Analysis on Stamps by Fourier Transform Infrared Spectroscopy," Appl. Spectrosc. 42, 1466-1469 (1988)