Association of Counterfeit Documents to a Printing Plate by Means of Halftone Dots

Several printing plates, proofs, suspect documents and genuine documents were submitted for examination. Comparison of the printing established that the suspect documents were counterfeit. Comparison of the halftone dots to the printing plates, proofs and suspect documents under high magnification (X80) established a similarity in the numbers, shapes, sizes and connectivity of the dots. Using these patterns, it was possible to distinguish between 6 equivalent images on the cyan printing plate and to say which was associated with a specific suspect document. A determination could be made that the printing plates, proofs and suspect documents shared a common source.