| Type of Forgery | Characteristics | Examination Techniques | Examples |
|---|---|---|---|
| Freehand Forgery | Attempt to mimic someone’s handwriting without tracing | Analysis of handwriting slant, pressure, letter formation | Forged signatures on checks |
| Tracing Forgery | Direct copying of genuine handwriting using tracing | Overlapping ink strokes, unnatural pen lifts, light table examination | Signing legal documents fraudulently |
| Simulated Forgery | Skilled imitation of genuine handwriting | Detailed comparison of natural writing habits | Faking endorsements |
| Cut-and-Paste Forgery | Using pieces of a genuine signature or text | Detection of glue marks, inconsistencies in baseline | Altering contracts |
| Electronic Forgery | Altering digital signatures or scanned documents | Metadata analysis, pixel-level inspection | Falsifying scanned IDs |
| Obliterations | Intentional covering of original writing | Infrared or ultraviolet (UV) light to reveal hidden text | Changing amounts on checks |
| Alterations | Adding or removing parts of a document | Chromatographic ink analysis, document layering | Altering birth certificates |
| Erasures | Removing text by mechanical or chemical means | Microscopic examination, UV light to detect erasure marks | Tampering with contracts |
| Check Washing | Removing ink from checks | Analysis of ink solubility, infrared spectroscopy | Changing payee names |
| Photocopy Forgery | Using photocopiers to manipulate documents | Analysis of toner, checking alignment and spacing | Falsifying government forms |
| Disguised Writing | Deliberate alteration of personal writing style | Analysis of consistent habits like stroke direction | Anonymous threat letters |
| Charred Documents | Partially burned documents | Reflective lighting, infrared photography | Recovering evidence after arson |
| Indented Writing | Impressions left on underlying pages | Electrostatic Detection Apparatus (ESDA), oblique lighting | Identifying source of anonymous notes |
| Counterfeit Documents | Complete replication of a document | Paper texture analysis, UV light to detect security features | Faking currency, passports |
| Fraudulent Documents | False information added to genuine forms | Verification of ink and handwriting | Falsifying loan applications |
| Typewriter Forgery | Using old typewriters to create or alter documents | Analysis of typeface, ribbon impressions | Manipulating historic letters |
| Watermark Alteration | Changing or imitating watermarks | UV light to detect original watermarks | Faking official documents |
| Overwriting | Adding additional strokes to existing text | UV and microscopic examination | Changing dates or amounts |
| Seal Forgery | Imitating or replicating official seals | Analysis of impressions, ink, or embossing | Fraudulent certifications |
| Ink Differentiation | Detecting use of multiple inks in a document | Thin Layer Chromatography (TLC) | Altered wills or contracts |
| Age Determination | Estimating the time a document was created | Ink drying patterns, carbon dating | Authenticating historic documents |
| Digital Signatures | Faking or tampering with electronic signatures | Certificate validation, encryption checks | Fraudulent financial agreements |
| Invisible Inks | Writing with ink visible under special conditions | UV light, chemical analysis | Espionage-related documents |
| Multi-page Document Analysis | Analyzing coherence across multiple pages | Paper fiber consistency, ink matching | Fake contracts or treaties |
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