Akademik Veri Yönetim Sistemi
European Academy of Forensic Science (EAFS 2025) , Dublin, İrlanda, 26 - 30 Mayıs 2025, (Yayınlanmadı)
Printers can leave toner particle residues on paper outputs, depending on the printer's brand and frequency of use. Previous studies have explored the distribution of these toner residues on documents, particularly about signed before-printing documents, and showed toner particle distribution on the signed area gives the idea for printing and signing sequence. However, the amount of toner contamination and whether the distribution of particles on the front and back surfaces of the paper is consistent has not been thoroughly examined. This study aimed to determine whether the distribution of toner particles was characteristic and whether toner particle contamination levels on the back surface of a document were similar to those on the front. Blank paper samples were passed through 22 distinct printers with dissimilar uses, and toner residues were counted in 25 different parts of the paper using small circles with a 1 cm radius, on both the front and back surfaces of the paper. The number of toner particles in each circle was counted using the ImageJ program. The results showed that the distribution of particles on both surfaces was random, with a higher number of particles found on the front surface compared to the back. These findings suggest that toner particle contamination may not be uniform across both surfaces of a document and that the presence of particles is influenced by printer usage frequency. This study contributes to understanding the nature of toner distribution, which could have implications on print-based questioned documents for forensic document analysis.