What is ink dating
Benzyl alcohol is also commonly used as the vehicle (solvent) by some ink manufacturers.
Knowledge of the composition of inks is necessary to understand the reasons for the various methods used to analyze inks.When dating tags are detected, it is possible to determine the actual year or years when the ink was manufactured.Dating tags are unique chemicals that have been added to ball-point inks by some ink companies as a way to determine the year the ink was made.The composition is basically the same, but this ink does not become fluid until disturbed by the rotation of the ball point in the socket.Cartridges containing this ink are under the pressure of nitrogen or some other inert gas.These ingredients consist of fatty acids, resins, surface active agents, corrosion control ingredients and viscosity adjustors.
The fatty acids (oleic is the most common) act as lubricants to the ball of the pen and they also help the starting characteristics of the ball point.
This explains the origin of the name blue-black fountain pen ink. This ink is insoluble in water and cannot be effectively erased by abrasion.
The most popular fountain pen ink (developed in the 1950s) consists of an aqueous solution of synthetic dyes.
There are two types of fountain pen inks: (1) iron-gallotannate type and (2) aqueous solutions of synthetic dyes.
Modern inks of type (2) contain synthetic blue dyes to provide an immediate blue color to the ink which gradually turns black after oxidation on paper.
In cases where known dated writings are not available for comparison with questioned inks, accelerated aging (heating the ink to induce aging of the ink) can sometimes be used to estimate the age of ink using any or all of the above described techniques.