ColorSwitch™
Hueck Folien GmbH (Austria)
Type: Colour-shift security thread — tilt-activated optically variable effect available in three distinct technology variants
Overview
ColorSwitch™ is the core colour-shifting security thread technology developed and manufactured by Hueck Folien GmbH, an Austrian security film and foil specialist headquartered in Baumgartenberg, Austria, and founded in 1970. One third of the world's currencies already bear Hueck Folien's high-security product solutions, including the Euro and the Swiss Franc. ColorSwitch™ is Hueck Folien's primary overt public authentication thread offering, providing a tilt-activated colour-shift effect that is immediately visible without tools under normal ambient lighting. It is not a single product but a family of three technologically distinct series, each using a different optically variable mechanism, giving it the broadest colour palette of any colour-shift thread on the market.
Notably, ColorSwitch™ also functions as a foundational technology layer within several of Hueck Folien's more advanced compound security features, including Trilumic® (developed jointly with Banque de France, combining ColorSwitch™ with UV holographic properties), Optomove® (combining ColorSwitch™ thin-film colour with micro-optical movement effects), and Nanoswitch® (combining ColorSwitch™ with IQ Structures' nanofabricated optical elements).
Technology & Effects
When tilting the banknote, the colour of the security thread changes. ColorSwitch™ comes in three series with distinct characteristics.
The L Series uses liquid crystal inks to produce the colour-shift effect, offering five colour shades. Liquid crystal-based colour shifting exploits the temperature- and angle-dependent optical properties of cholesteric liquid crystal pigments, which selectively reflect specific wavelengths depending on the viewing angle, producing a vivid and sharp colour transition.
The G Series uses optically variable inks containing colour-shifting pigments — thin-film interference pigments — offering a palette of more than 30 shades, enabling precise colour matching with a banknote's existing print design scheme. This is the broadest colour selection of any colour-shift thread series offered by any supplier.
The P Series is specifically engineered for design coordination with SICPA's SPARK® colour-shift ink feature, offering six colour shades calibrated to match SPARK® colour pairs. This enables seamless visual integration between the thread and a note's OVI ink elements, producing a coherent and distinctive authentication story across the full banknote design. Optomove®, Hueck Folien's micro-optical thread, features six ColorSwitch™ shades based on high-precision thin-film technology, demonstrating that the P Series thin-film platform also underpins the company's advanced compound features.
Form Factors & Application
ColorSwitch™ is supplied as a windowed security thread embedded in banknote paper during manufacture. It is compatible with all standard security paper mills worldwide, and Hueck Folien has been directly collaborating with most security paper mills for more than 30 years. The thread can incorporate additional security elements including demetallized clear text (denomination, central bank initials), UV-fluorescent properties, and machine-readable magnetic or conductive codings, enabling it to serve simultaneously as a Level 1 overt feature and a Level 2 machine-readable feature within a single thread.
Security Levels
ColorSwitch™ operates at Level 1 (public) as a tilt-activated colour change that is immediately visible and unmistakable under ambient lighting — a well-established and universally recognisable authentication gesture requiring no tools. The breadth of the colour palette (particularly the G Series' 30+ shades) means that each central bank's colour pair is unique and difficult to match without access to Hueck Folien's proprietary pigment formulations. Optional machine-readable codings elevate selected configurations to Level 2. When deployed as part of Trilumic® with UV holographic imagery or as part of Optomove® with micro-optic movement, the overall feature system achieves substantially higher security barriers.
Notable Deployments
Hueck Folien does not publicly name specific central bank deployments by country for individual thread products. However, Trilumic® — which builds directly on ColorSwitch™ technology — has documented deployments including a Moroccan 50 dirham banknote incorporating a Trilumic windowed thread with a dynamic blue-to-green colour shift, produced by Morocco's printworks Dar As-Sikkah, and Cambodia's 15,000 and 20,000 riel commemorative banknotes featuring Trilumic in stripe format. Given that Hueck Folien supplies threads to approximately one third of the world's currencies, ColorSwitch™ in its standalone G Series form is among the most widely deployed colour-shift thread technologies in global circulation.
- Name
- ColorSwitch™
- Category
- Security Feature
- Effect Types
- Colour shift
- Company
- Product Page
- View on Supplier Site
- Linked Features
- 2 security features