When design meets physics

Thermochromic inks react to changes in temperature. At a specific threshold, they lose or gain color – allowing the product to “tell” when it has reached the ideal temperature for use.

The principle is based on microcapsules with leuco dye, which contain three essential components:

• Leuco dye – the coloring agent that can exist in either a colored or colorless form
• Developer – a substance that forms a color complex with the dye
• Solvent – a medium that changes its state depending on temperature and thus influences the dye–developer bond

At low temperatures, the solvent is solid, the dye binds to the developer, and a visible color appears (for example, deep blue). When the temperature rises, the solvent melts, the bond breaks, and the pigment becomes invisible – the print optically disappears. After cooling, the process reverses and the color reappears. This reversible cycle can be repeated thousands of times without losing its effect.

Technological implementation

At Authentica GlassDecor, we apply thermochromic inks using direct screen printing on a Kammann K24 printer, which ensures precise registration even on curved glass surfaces, or by coating with electrostatic and automatic spray guns. The decorated containers are then cured at low drying temperatures (up to 150 °C) in an electric industry oven.

To achieve the desired effect, a combination of standard ink (static motif) and a thermochromic layer (dynamic motif) is often used. This results in a multilayer design that is both visually striking and functionally engaging.

Thermochromic inks can be fine-tuned to react at different temperature thresholds (e.g., –5 °C, +10 °C, +20 °C) depending on the product’s requirements. The inks are applied in one or more layers, and after curing, they become fully integrated into the surface structure of the decoration.

A technology that creates an experience

At first glance, it’s a visually impressive effect – but its true strength lies in the fusion of function and emotion. What starts as an ordinary print becomes an interactive medium that draws the consumer in – showing the exact moment when the product is ready to enjoy.

This principle is widely used for beverages served chilled (wine, cider, beer, soft drinks), coffee and tea where color change signals the optimal drinking temperature (preventing burns), or cosmetics, where temperature can indicate the activation of ingredients when warmed.

Cool John: proof that technology can be an experience

A perfect example is the Cool John red wine from the Scheiblhofer winery – the first wine meant to be served chilled.

Here, thermochromic printing plays a key role: at temperatures above 14 °C, the motif is almost invisible, but once the wine is properly cooled, the design lights up in a vibrant blue color – a clear sign that it’s time to open the bottle.

We decorated approximately 300,000 bottles of Cool John at Authentica GlassDecor using direct UV screen printing on our Kammann K24 machine. The project won 1st place in the Packaging of the Year 2025 competition in the Processes & Technology category.

When technology and emotion go hand in hand

Thermochromic printing demonstrates how chemistry, technology, and design can create something truly extraordinary – a package that not only attracts attention but also communicates.

And that’s exactly what drives us at Authentica GlassDecor: creating products that don’t just look beautiful – they live their own story.