ISSN: 0022-1198
CODEN: JFSCA
Published Online: 1 September 2003
Page Count: 9

The Forensic Analysis of Thermal Transfer Printing
(Received 3 April 2003; accepted 29 March 2003)

Abstract

Thermal transfer printing refers to printing processes that utilize heat to produce an image by either physical or chemical means or by a combination of both. As the technology has improved and the supplies have become less expensive, the use of thermal printing in the personal and business markets has increased significantly. Specifically, dye diffusion thermal transfer and thermal mass transfer have become predominant in the production of counterfeit credit cards, drivers' licenses, and other types of documents produced on plastic media. Chemical analysis by means of thin layer chromatography (TLC) has proven to be useful in characterizing various types of inks (e.g., writing and inkjet inks). In this study, the authors examined 81 different samples that included a total of 54 printer samples (43 photographic prints on paper and eleven plastic card samples) and 27 printer ribbons. A new TLC method was developed and tested utilizing a solvent system (80% n-hexane, 3% methyl ethyl ketone, and 17% ethyl acetate) that is capable of producing excellent resolution.

Keywords:
forensic science, questioned documents, counterfeit documents, identity documents, thermal transfer printing, dye diffusion thermal transfer, thermal mass transfer, printing processes, thin layer chromatography, ink analysis

Paper ID: JFS2003026
DOI: 10.1520/JFS2003026
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