Interestingly enough, the ink in these pens will actually reappear when the temperature reaches below - 10 C (under 14 Fahrenheit). a freezer is sufficiently cold enough to make the ink start to reappear. It is like a Magic pen for adults! because the ink in this pen is thermos sensitive, we do not advise for it to be left in Hot cars, used for mailing, or subjected to a condition that exposes it to a lot of fruition.
Friendly Guarantee:
All products sold by us have been 100% QC tested, we promise the 30-day money back and 180-day free replacement. If there is any quality issues, please don't worry, we will provide 24h*7d timely customer service to solve the problem better.