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.
Related terms
- Chain of Custody
- The documented chronological record of who collected, handled, transferred, and examined a piece of evidence. For digital evidence, chain of custody includes...
- 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...
Explained in
- Lab Equipment, Evidence Handling and Chain of Custody in QDEPaper folders or envelopes manufactured without acidic buffers, used for long-term storage of questioned documents to prevent acid-catalysed paper and ink degr...