Water-Sensitive Ink Applications｜Water-Activated Color Change, Omikuji Fortune Paper & Anti-Counterfeit Printing

#WaterSensitiveInk (also known as #MoistureReactiveInk) is a type of specialty ink that changes color upon contact with water. The most common version appears white when dry and turns transparent or colorless when wet. When printed over a colored design, the water-sensitive ink transitions from white to reveal the full-color image underneath after contact with water.

Omikuji Fortune Paper | Hidden Messages Revealed with Water

The printing technique used for water omikuji is quite unique. When dry, the paper appears blank with no visible text. Once it comes into contact with water, the paper becomes translucent, revealing hidden messages or images.

This type of fortune-telling is commonly seen at Japanese shrines, where visitors draw random Omikuji paper slips. After placing them on water, the hidden messages appear, enhancing both the interactive experience and the spiritual significance of the ritual.

Once dried, the hidden text typically disappears again. However, repeated exposure to water may cause the printed letters to blur over time, reducing detail clarity.

Moisture-Reactive Ink for Tamper-Evident Security Labels

In anti-counterfeiting applications, moisture-reactive ink is often used for tamper-evident seals. If a counterfeiter attempts to soak and remove the label, the ink will change color upon contact with water, leaving an irreversible mark as proof of tampering.

These inks typically shift from a visible color to transparent and do not return to their original state after drying. This irreversible color change acts as clear evidence of unauthorized access, making them ideal for secure packaging and product authentication.