Manufacturing Change Window
Definition
The interval between when an ink formulation was introduced and when it was discontinued or reformulated; documents with ink outside this window for their purported date indicate anachronism or alteration.
- Defines
- Period an ink formulation was in production
- Bounded by
- Introduction date and discontinuation or reformulation date
- Use
- Detects anachronistic or altered documents
- Source data
- Manufacturer formulation records and ink libraries
Common questions
How does an examiner determine that ink falls outside its manufacturing change window?+
The ink is analysed, typically by thin-layer chromatography or mass spectrometry, for dye or additive markers known from manufacturer records to have entered or left the formulation on specific dates, and the resulting chemical profile is matched against a reference ink library indexed by those dates.
What does a finding outside the manufacturing change window actually prove about a document?+
It shows the ink could not have been produced at the time the document is dated to, which supports a finding of backdating or later alteration of an entry, but it does not by itself identify who made the change or when it actually occurred.
Related terms
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- USSS International Ink Library
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