Ink Dating

Ink “Dating” – What is it? – Ink Dating, Ink Age, Forensic Analysis Ink, Fraud, Forgery

Ink Dating PicThere are typically two different forensic methods for ink dating. The first method used is known as the “static” approach. With this method the forensic analysis determines the components in the ink, compares them against a library of standards and then allows an opinion regarding the first date that particular ink was manufactured (commercially available). The second method is known as the “dynamic” approach in that it focuses on changes occurring within the ink as it ages. The dynamic approach is very useful in determining if a pen ink was placed on a document on its purported date, i.e. the date shown on the document, or else, instead whether the ink was placed on the paper more recently.

There are only a handful of forensic scientists capable of performing these tests and laboratories equipped with the proper tools. These experts would typically use methods including visual and microscopic examinations, ultraviolet fluorescence, infrared luminescence/absorbance, thin layer chromatography and sometimes expensive equipment such as gas chromatography/mass spectrometry (GC/MS), Fourier Transform Infrared Spectroscopy (FTIR) and Xray fluorescence spectroscopy (XRF).

What are the typical ink analysis procedures?

Forensic ink testing is performed on Original Documents and may include: a) visual analysis with microscope/magnification device; b) infrared and ultraviolet analysis; c) electrostatic detection; d) thin layer chromatography; and e) gas chromatography/mass spectrometry. The proposed tests are minimally invasive, the latter two involving the placement of pinhole perforations in the text, paper and signatures on the Original Document. The pinholes themselves are not typically easily visible unless the document is held up to light, and the testing has no negative effect on handwriting analysis.

All of the proposed testing follows Court approved testing methods, e.g. those published by the American Society for Testing and Materials (ASTM) or other peer reviewed and approved forensic methodology.

Why is ink analysis allowed if a document is in question?

Code of Civil Procedure §2031.010(a) permits a party to inspect and photograph, test or
sample any tangible things that are in the possession, custody or control of the party on whom the demand made. Under appropriate circumstances, the Court may order destructive testing of all or some portion of the physical item in question. See, San Diego Unified Port Dist. v. Douglas E. Barnhart, Inc. (2002) 95 Cal. App. 4th 1400, 1404, 116 Cal. Rptr. 2d 65.


Inks appearing on questioned documents may be examined for the purpose of comparing with other inks on the same document, with ink on other documents or even with ink in seized pens. Sequence of entry can sometimes be determined. Questions regarding manufacturer, pen, pen type, ink age, backdating, fraud and forgery can often be answered by Larry Stewart, Global Forensic Services, LLC.


Non-destructive techniques used in the analysis of inks involve microscopic examinations and the use of various wavelengths of radiation (e.g., visible light, infrared and ultraviolet radiation, filters, etc.). Although useful in the elimination of some inks, these techniques are not as definitive as destructive techniques, in which small discs are removed from the ink lines.

By utilizing destructive techniques, it is possible to determine if two inks on the same or different documents are of the same formulation or if the ink on a document and the ink in a seized pen are of the same formulation. By comparing with a library of ink standards it is possible to determine the manufacturer of the ink and the date it was introduced (useful in detecting backdated documents).


All evidence should be inventoried and submitted with the request letter outlining the writing ink analysis. Specify the entries in question and include a notation to indicate that a comparison is to be made between certain inks or between inks on documents and inks in writing pens.


Sometimes the date of a written ink entry on its own or else relative to other entries on the same document is questioned. Chemical tests can be conducted that may determine how long the ink has been on the document and whether a document entry has been falsely dated. Documents bearing such entries may be single page documents or bound documents, such as journals, calendars or diaries. A destructive technique is used for this examination, i.e., small samples of the ink line are removed from the paper.

Ink dating may be performed on ballpoint pen inks. Currently, it is estimated that approximately 85% of ballpoint pen inks are manufactured using a chemical component known as, 2-phenoxyethanol or PE. Larry Stewart was the first to recognize the importance of this in his 1985 publication, “Ballpoint Ink Age Determination by Volatile Component Comparison – A Preliminary Study,” Journal of Forensic Science, Vol. 30, No. 2, April, 1985. There he noted phenoxyethanol and that the concentration changed over time or with heat/evaporation. Even then, the research showed some inks had reproducible aging characteristics that could be reliably measured with gas chromatography. His initial research, observations and publication gave rise to the current approach for testing ink age.


It is possible to determine that an entry on a questioned document was placed on that document at a time other than that indicated.


All documents submitted should be properly inventoried and submitted to the lab.

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