The three magic inks in the RUNED universe react differently depending on light and temperature.
Heat-sensitive ink
This ink disappears at temperatures above 29°C and becomes visible again at colder temperatures.
At the height of summer, the ink may not return as long as it is too warm.
In winter, the ink has to reach at least 29°C to disappear.
If your fingers are too cold, the ink will not work by hand. Instead, use a heater or a hairdryer at a sufficient distance.
⚠ Caution: Never heat book pages with an open fire - fire hazard!
RUNED 2 does not contain this heat-sensitive ink.
The two UV inks
Ink A: This ink only glows in the dark after it has been charged with a UV lamp.
Ink B: This ink is only visible under direct UV radiation, but does not glow in the dark.
If the inks do not react as expected, check the lighting conditions and temperature. Have fun discovering the hidden clues!