To make erasable pen ink reappear, you typically need to cool the paper down, as the ink used is often thermo-sensitive.
Bringing Back "Erased" Ink
Many erasable pens use special thermo-sensitive ink that disappears when heated by the friction of the eraser. Fortunately, this process is reversible. If you find that writing from such an erasable pen has vanished, often due to heat or simply the passage of time, the solution is straightforward: expose the paper to a cold temperature.
According to the provided reference, thermo-sensitive ink used in these pens typically reappears at around -10°C.
The Simple Method
The most common and effective way to achieve the necessary cold temperature is by using a freezer.
- Place the item in the freezer: If you have a page where the writing has disappeared, simply put it in the freezer for a short period of time.
- Allow it to cool: The ink will reappear as the paper reaches a sufficiently cool temperature. As mentioned, this thermo-sensitive ink reappears at approximately -10°C.
- Check for reappearance: Once the pages sufficiently cool, your work should reappear once more.
This cold method effectively reverses the process that made the ink invisible, allowing the color molecules in the thermo-sensitive ink to become visible again.
Note: This method works specifically for pens that use thermo-sensitive, heat-erasable ink, not for pens that use friction to scrape traditional ink away.
Understanding Thermo-Sensitive Ink
Erasable pens often utilize a unique ink formula containing three key components:
- Pigment: Provides the color.
- Developer: Reacts with the pigment.
- Modulator: Controls the reaction between the pigment and developer based on temperature.
When heated (by erasing friction), the modulator changes state, preventing the pigment and developer from reacting and thus making the ink colorless. When cooled, the modulator returns to its original state, allowing the reaction to occur again and the color to reappear.
This temperature-dependent reaction is why simply putting the paper in a cold environment like a freezer is an effective way to restore faded or disappeared writing from these types of erasable pens.
