Organizing a Proficiency Testing Program on Stamp Impressions Examination in Accordance with ISO/IEC 17043 Requirements.

Stamps and stamp impressions examinations are based on matching defects and design details on the questioned and control samples. These examinations are routinely carried out by document examiners around the world. International proficiency tests for questioned documents examination have been available for decades while similar programs specifically focusing on stamp impressions examination are rare. This study reported a recent proficiency testing program on stamp impressions examination organized by an accredited provider in accordance with ISO/IEC 17043 requirements. Twenty-four forensic laboratories registered for the program. Apart from giving details on the design and operation of the program, this study also aimed to provide the limitations and difficulties encountered in sample preparations, homogeneity, and stability tests of the testing materials. Various comments and feedbacks received from the participants, particularly in respect of examination approaches, challenges faced by the participants in forming conclusions and their suggestions for further improvement would be evaluated.