ISSN: 0022-1198
CODEN: JFSCA
Published Online: 1 May 1992
Page Count: 12

Some Special Observations Regarding Visible Transmission Spectra of Inks and an Improved Method for Their Discrimination by Microspectrophotometry
Zeichner, A
Head and Scientific Officer, Toolmarks and Materials Laboratory, Division of Identification and Forensic Science, Israel Police Headquarters,

Glattstein, B
Head and Scientific Officer, Toolmarks and Materials Laboratory, Division of Identification and Forensic Science, Israel Police Headquarters,

Abstract

Various blue and black inks are shown to change their transmission spectra by applying pressure and smearing them as deposits on glass slides. A similar phenomenon is observed with deposits of copper phthalocyanine tetrasulfonic acid tetra sodium salt. It is shown that transmission spectra of small samples of inked paper fibers smeared (crushed) on glass slides resemble spectra of smeared ink deposits and are more reproducible than spectra of inked fibers in a mounting medium. This advantage is especially significant in the case of examining ink traces on tinted paper.

Keywords:
questioned documents, inks, spectroscopic analysis, microspectrophotometry

Paper ID: JFS11986J
DOI: 10.1520/JFS11986J
ASTM International is a member of CrossRef.