Ink dating techniques
The use of different wavelengths of the electromagnetic spectrum provides an examiner with a large number of different techniques to determine the optical properties and some of these techniques are used routinely to reveal, faded, erased and obliterated entries (pencil and ink ) or used to examine damaged documents which have been burnt, water or solvent affected or even digested!In situations where the inks have similar optical properties, and appear indistinguishable there will be a need to resort to further non destructive analysis (microspectrophotometry etc.,) or destructive techniques were inks samples are removed from the substrate and the dyes of the inks are chemically extracted and analysed using a variety of methods although different techniques are utilised for Gel inks.There are only a handful of labs in this country that do this kind of analysis.
We consulted with our curators and decided that we could use a few of these small fragments for C-14 analysis.
Parchment is a writing material made from specially prepared untanned skins of animals—primarily sheep, calves, and goats.
It has been used as a writing medium for over two millennia.
The equivalent material made from calfskin, which was of finer quality, was known as vellum (from the Old French velin or vellin, and ultimately from the Latin vitulus, meaning a calf); while the finest of all was "uterine vellum", taken from a calf foetus or stillborn calf.
Some authorities have sought to observe these distinctions strictly: for example, lexicographer Samuel Johnson in 1755, and master calligrapher Edward Johnston in 1906.
A common issue in sexual assaults is the ability to differentiation sexual lubricants from personal hygiene products (PHPs) such as lotions.