Skip to content

Solvent-Loss Method

Definition

An ink dating approach that measures the residual concentration of semi-volatile solvents (particularly phenoxyethanol in ballpoint inks) relative to a non-volatile reference; the ratio decreases with age as solvent evaporates or migrates into the paper fibre network.

Related terms

Aging Index (Aginsky)
The ratio of phenoxyethanol concentration in an unheated (cold) extract to its concentration in a heated extract from the same ink stroke;...
ASTM E2494
ASTM International's Standard Guide for Using Ink Examination Methods in Questioned Document Investigations; sets out the recommended tiered analytical approach, uncertainty reporting...
Dye-Decay Dating (LaPorte Method)
An ink dating method that uses HPLC-PDA to monitor the relative concentrations of specific dye components and their degradation products; the ratio...
Machine Direction (MD)
The direction parallel to paper travel through the papermaking machine; cellulose fibres preferentially align in this direction, making machine-made paper stronger and...
Optical Brightening Agent (OBA)
A fluorescent compound added to paper pulp or coatings that absorbs UV-A radiation and re-emits it as visible blue light, making paper...
Plateau Effect
The upper age limit of ink solvent-loss methods (approximately 5-7 years in most storage conditions), beyond which phenoxyethanol has been substantially lost...
Rag Paper
Paper made from cotton or linen rags, yielding long, low-lignin cellulose fibres; the dominant writing-paper substrate before approximately 1870 and still used...
Terminus Post Quem
Latin for 'limit after which'; in document dating, the earliest possible date for a document, established when a material component (paper, ink,...
Watermark
A pattern formed in paper during manufacture by localised fibre-density variation on the Fourdrinier wire; visible in transmitted light as a lighter...

Explained in

Your journey to becoming a forensic professional starts here.

Practice with mock tests, learn from structured notes, and get your questions answered by a global forensic community, all in one place.