title: Dating of inkpad seals using the extraction rate method: preliminary findings.
abstract: Inkpad seals are often placed on important documents, and determining the date when a seal was affixed can be important to assess the authenticity of a document. In this study, three different brands of inkpads and four different types of paper were used to make diachronic samples of the seals. A double-solvent extraction method was employed to date the inkpad seals by comparing extraction rates with inks of known age. Cyclohexane was selected as a weak solvent, and chlorobenzene was selected as a strong solvent. After testing, curves were created to show the relationship between the extraction percentage of ink and the date of the seals. The experimental results showed that the extraction rate method was applicable for the relative dating of inkpad seals in some cases where the seal was placed on the document within 6 months.
authors: Department of Document Examination, China Criminal Police University, No. 83 Tawan Str., Shenyang City, 110854, China.
authors: Biao
authors: B
authors: Li
authors: Feng
authors: F
authors: Bai
authors: Huayan
authors: H
authors: Mu
authors: Ren
authors: R
authors: Bao
keywords: dating of documents; dating of inkpad seals; document examination; extraction rate method; forensic science; inkpad seal; relative aging