Nondestructive forensic analysis of antique stamps by use of synchrotron radiation infrared spectromicroscopy

IEC 158

Tommy J. Wilkinson, Dale L. Perry, Michael C. Martin, and Wayne R. McKinney. Advanced Light Source, Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, CA 94720
Synchrotron-based Fourier transform infrared spectromicroscopy (FTIR SM) has been used to study and characterize Canadian 3-cent Victorian era "Small Queen" stamps. This series of stamps was printed and issued over 25 years by a single source, but were printed at different locations, and using imprecise ink composition mixtures, resulting in very subtle differences among them that are often difficult to discern. Many current analytical methods are destructive, and non-analytical methods are subjective, more art than science, and may affect the rarity and price of the stamps. The paper and paper/ink chemistry is exceedingly complex, varying from microdomain to microdomain. Changes in the paper and ink are identified and discussed.

This work was supported by the Director, Office of Science, Office of Basic Energy Sciences, Materials Science Division, and the Office of Science Education of the U. S. Department of Energy under Contract Number DE-AC03-76SF00098.