ESDA (Electrostatic Detection Apparatus)
Definition
A non-destructive technique for detecting indented impressions on paper caused by writing pressure. A physical ink signature on paper produces detectable ESDA traces; a printed or digitally imposed signature does not. Remains the primary countermeasure against printed AI-generated signatures.
- Standard instrument
- Foster+Freeman ESDA 2
- Detection method
- Electrostatic charge pattern from paper deformation, visualized with toner
- Detectability of printed signatures
- No indented impressions left, making ESDA a primary countermeasure against printed AI-generated signatures
Common questions
What is ESDA and what does it detect?+
ESDA is an electrostatic detection apparatus that reveals latent indented writing impressions on paper. It works by converting the microscopic surface deformations created by pen or pencil pressure into a visible pattern using charged toner on a Mylar film. The result is a permanent, high-contrast image of hidden writing.
How does ESDA help detect forged documents?+
ESDA can reveal original writing that has been chemically washed away, overwritten, or covered up. It is particularly useful for detecting printed or AI-generated signatures, which leave no indented impressions. A genuine handwritten signature creates detectable ESDA traces, while a printed or digitally imposed one does not.
Is ESDA damaging to documents?+
No. ESDA is a non-destructive technique, meaning it does not harm or alter the original evidence. The toner is applied to a film placed over the document surface, not to the document itself.
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- Corona Wire
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Explained in these topics
- AI-Generated Documents, Deepfake Signatures and Image ManipulationA non-destructive technique for detecting indented impressions on paper caused by writing pressure. A physical ink signature on paper produces detectable ESDA...
- Cheques, Demand Drafts, Stamps and Seals: Forgery PatternsAn instrument that reveals latent writing impressions (indentations left by a pen or pencil on the sheet beneath a written document) by applying a charged tone...
- Indented Writing and the ESDA Electrostatic Detection ApparatusAn instrument that converts the micro-topographic indentations in paper into an electrostatic charge pattern developed with toner, producing a permanent high-c...
- Lab Equipment, Evidence Handling and Chain of Custody in QDEA forensic instrument (Foster+Freeman ESDA 2 is the current standard) that detects indented writing on paper by exploiting the differential electrostatic charg...