Acid-Free Packaging
Definition
Paper folders or envelopes manufactured without acidic buffers, used for long-term storage of questioned documents to prevent acid-catalysed paper and ink degradation.
- Material
- Paper folders and envelopes
- Property
- Manufactured without acidic buffers
- Use
- Long-term storage of questioned documents
- Prevents
- Acid-catalysed paper and ink degradation
Common questions
Why does ordinary paper packaging harm documents over time?+
Standard acidic paper releases compounds that migrate into stored items and accelerate yellowing, brittleness, and fading of certain inks, so a document kept in it for years can lose diagnostic detail before it is ever examined.
Does acid-free packaging affect how a document can be examined later?+
No, it is inert packaging chosen purely for preservation; it does not interfere with later ink, indentation, or fibre analysis and is standard practice for any document intended for long-term retention.
Related terms
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- ESDA (Electrostatic Detection Apparatus)
- A non-destructive technique for detecting indented impressions on paper caused by writing pressure. A physical ink signature on paper produces detectable ESDA...
- IR Luminescence
- Emission of near-infrared radiation by ink dye molecules when excited by visible light; different ink formulations luminesce at different intensities, allowing differentiation...
- IR Reflectance
- Imaging under near-infrared illumination (715-1000 nm) to differentiate inks by their IR absorption: carbon-based inks remain dark, many synthetic dye inks become...
- Mylar (Polyester) Sleeve
- A chemically inert, optically clear polyester film sleeve used to protect questioned documents during examination and archival storage without introducing chemical contaminants...
- Oblique Illumination
- Lighting applied at a very low angle to the document surface (below 10 degrees from horizontal) to reveal topographic features: writing indentations,...
- Transmitted Illumination
- Lighting passed through the document from the back face to reveal paper-body features invisible from the surface: watermarks, security threads, and paper-thickness...
- UV Fluorescence Examination
- Examination under 365 nm or 254 nm ultraviolet light to reveal optical brightener fluorescence in paper, ink luminescence, and areas of altered...
- Video Spectral Comparator (VSC)
- A multispectral imaging instrument combining UV, visible, and near-infrared illumination with selectable emission filters and a calibrated digital camera; the primary bench...