Ink dating test
Ink dating test
Some inks fluoresce, or emit light, on exposure to ultraviolet, while others disappear.Each ink should give a distinct pattern or spectrum on exposure to ultraviolet or visible light.
For these reasons a direct dating of ink lines is seldom carried out by this Laboratory.
The plate is then placed in a developing tank and a solvent system is added to the chamber.
The specific solvent system is chosen based on the type of ink being tested.
It involves removing several "plugs" of ink and paper from the document, placing them in a small vial where a solvent is added to dissolve the ink.
Once extracted, the ink is spotted on a high performance plate.
Although all blue or black inks may look the same, there can be some important differences in their chemical composition.
These can be revealed by laboratory analysis and the results can help assess whether there have been any additions or alterations to a document.
The band patterns corresponding to ink removed from three different areas of a document (Figure 1) show that samples #1 and #3 have a similar formulation while ink #2 contains different components than the other two.
This supports the Plaintiff's claim that the document was altered sometime after he signed it.
Differentiating inks can be important in cases where a document is suspected of having been altered.
A classic example is where a zero is added to a cheque making the value ten times as much.
The fact that two inks are indistinguishable does not prove that they both came from the same pen as a large number of pens are likely to hold indistinguishable ink either because they originate from the same manufacturer or because, by chance, they contain closely similar ink.