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Photochromic Ink

Walk outside into the sunlight and watch packaging printed with CTI photochromic technology burst into color. What seems like magic is, in reality, sophisticated chemistry. Here’s how it works: When sunlight or UV light containing 365-nanometer wavelengths stimulates sunlight activated inks on printed materials, photochromic dye molecules rotate to change from colorless to color almost instantly. 

Sunlight Activated Ink Packaging Using Photochromic Ink

When prints are brought back inside or light is removed, the molecules rotate back slowly to their colorless state, which may take up to 15 minutes, depending on the dye color and environmental conditions. CTI offers photochromic inks in many high-speed commercial print formats, but the end result: amazing brand experiences and social media buzz.

out of the sun

in the sun

Advantages of Sunlight Activated Ink:


  • Printable technology, just like other high-speed commercial inks

  • Full control over brand identity, graphic design and placement, either through existing printed label or direct package/container printing

  • Combine with other technology like thermochromic inks for unique brand experiences

  • Long-term chemical stability

  • Reversible

  • Safe for indirect food contact

  • BPA-, BPF-, BPS-free and compliant with REACH, Prop 65, CONEG, and many other regulations. PVC (phthalate-free) formula available for Textile screen inks.

in the sun

out of the sun

Light and Shadow

Temperature Influence

Photochromic inks will function in any environment; however, color will be even stronger if the food or beverage package is cold.


Color Transition

Sunlight activated inks change from colorless to color when exposed to 365 nanometer light, either in sunlight or blacklight (UVA). When removed from UVA light, color will return to the residual (slight or no color, depending printed ink film weight) state after several minutes.


Industries and Applications

Beverages and Foods  Canned, bottled and fountain-served beverages; snacks in flexible packaging; warning messages for any product that should not be sunlight.

Clothing  Athletic wear



Textile Screen, Textile Screen PVC Free (Phthalate-Free), Water-based Screen, UV Screen, UV Flexo, Metal Deco, Water-based Flexo, Water-based Gravure, Solvent-Based Flexo, Solvent-Based Gravure, Wet Offset, UV Wet Offset, UV Dry Offset. Other formats may be available.

Available colors


Metal Decoration        

UV Flexo 

UV Screen 

Offset Color Chart

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