1. The Tactile Signature of Intaglio Ink (The "Banknote Feel")
The most critical physical property of banknote ink is its application via the intaglio printing process. This is not "printing" in the conventional sense; it is a high-pressure deformation of the substrate.
· Genuine: Specialized intaglio inks are forced into the paper under immense pressure (up to several tons), creating a raised, three-dimensional ridge of ink that is physically embedded into the paper fibers. This creates a tactile "crust" that stands roughly 50 micrometers (µm) above the surface. When you drag your fingernail across an intaglio-printed portrait or denomination numeral, you feel a sharp, glass-like, unbroken ridge. This is the unmistakable "banknote feel."
· Counterfeit: Offset or inkjet processes simply deposit ink on top of the surface. The ink layer is flat, thin, and lacks physical relief. When scratched, it feels slick, waxy, or like a cheap decal. There is no raised, three-dimensional structure.
2. The Optical Physics of Optically Variable Ink (OVI)
OVI is a sophisticated ink containing microscopic, multi-layer interference pigments. It is a physical, not just a visual, phenomenon.
· Genuine: The ink's color changes based on the viewing angle due to light interference (e.g., green to blue, magenta to green). This is a physical property of the ink's composition.
· Counterfeit: A counterfeiter can only approximate this with metallic or pearlescent paints, which may shimmer but do not exhibit a distinct, sharp color switch. The effect is often a dull, static sheen rather than a dynamic, angle-dependent color change.
3. The Chemical Composition: Magnetic and Fluorescent Inks
Modern banknotes use inks with specific, machine-readable chemical properties.
· Magnetic Ink: Inks can be formulated with magnetic iron oxide (Fe₃O₄). This allows machines to "read" the note and vending machines to authenticate it. Genuine inks use specific magnetic "signatures," such as low-coercivity "hard" inks. A forensic examination can reveal if a counterfeit uses a different magnetic material.
· Fluorescent Ink: Inks contain materials that glow under ultraviolet (UV) light. This is a chemical property, not a visual one. A genuine note will have specific, intricate patterns that glow in designated colors under UV light.
4. The Chemical Resistance: Solvent-Reactive Inks
Some security inks are designed to react to chemical alteration. Reactive ink is engineered to change color or degrade when exposed to solvents like bleach or acetone. This is a "tripwire" against attempts to chemically wash or alter a note.
5. Ink as a Carrier for Other Security Features
Ink is not just a pigment; it's a vehicle. It can carry:
· Microtext: The ink must have a fine enough consistency to hold characters that are only visible under magnification. A counterfeit's ink will often bleed, making microtext illegible.
· Taggants: Invisible forensic markers can be embedded within the ink itself, detectable only by central banks.
---
FINAL BOTTOM LINE FROM A CORRECTED LOCKSMITH'S PERSPECTIVE
Think of banknote inks as the pins and springs of a lock. You can visually replicate a key's shape, but without the precise metallurgy and spring tension, it won't work.
1. Tactile Profile (The "Bite"): Intaglio ink creates a physical ridge.
2. Optical Profile (The "Keyway"): OVI provides a specific, angle-dependent optical response.
3. Chemical Profile (The "Spring Tension"): Magnetic and fluorescent inks provide specific, machine-readable signatures that cannot be mimicked by standard commercial inks.
---
ADDITIONAL REFERENCES
· U.S. Currency Education Program – "Dollars in Detail": https://www.uscurrency.gov/sites/default/files/downloadable-materials/files/en/dollars-in-detail-guide-en.pdf
· U.S. Currency Education Program – $100 Note Security Features: https://www.uscurrency.gov/vi/node/75/index.html
· European Central Bank – Banknote Production and Security Features: https://www.ecb.europa.eu/euro/banknotes/production/html/index.ff.html
· European Central Bank – Quick Guide to Euro Banknote Security Features: https://www.ecb.europa.eu/euro/pdf/material/quickgde/Quick_Guide.en.pdf
· Bank of England – How to Check Your Banknotes: https://www.bankofengland.co.uk/banknotes/how-to-check-your-banknotes
· Bank of Japan – Security Features of Bank of Japan Notes: https://www.boj.or.jp/en/note_tfjgs/note/security/index.htm/
· Bank of Canada – How to Keep Fake Bills Out of Your Wallet: https://www.bankofcanada.ca/banknotes/security-features/
---
LOCAL CONTACT INFORMATION – ANAHEIM CITY COUNCIL
Anaheim City Council
200 South Anaheim Boulevard
Anaheim, CA 92805
Main Contact:
Phone: (714) 765-5166
Fax: (714) 765-4105
Email: cityclerk@anaheim.net
Website: www.anaheim.net
City Council Members (as of 2026):
Member Title District
Ashleigh E. Aitken Mayor At-Large
Carlos A. Leon Mayor Pro Tem District 2
Ryan Balius Council Member District 1
Natalie Rubalcava Council Member District 3
Norma Campos Kurtz Council Member District 4
Kristen Maahs Council Member District 5
Natalie Meeks Council Member District 6
Public Participation:
· Public comments are limited to three (3) minutes per speaker.
· City Council meetings are held at Anaheim City Hall, Council Chamber, 200 S. Anaheim Blvd., Anaheim, CA 92805.
· Meeting agendas and reports are available at www.anaheim.net/councilagendas.
· For disability-related accommodations, contact the Office of the City Clerk at (714) 765-5166 or cityclerk@anaheim.net at least 72 hours prior to the meeting. ← Back to Fiveo1