Looking for Valentine’s activity that feels like a magic trick? Say hello to the ‘Cold Heart’ Secret Message. All you need is a Valentines Card, an eraseable pen and a hairdryer!
Things You Will Need
- Valentines Card with a space for a secret message – download our free printable Valentines Card here
- Coloured pencils/pens to make it beautiful
- An erasable pen (Legami, Pilot Frixion, and other brands marked as erasable or thermochromic)
- Hairdryer (or other safe heat source!)
Note about Erasable pens
We like to use Legami pens as they are refillable and come in lots of colours and adorable designs but there are other ranges possible. Please check this video to see if your pen is of the right type:
Instructions
1.
Select the erasable pen you wish to use and write your secret message on the card
2.
Using a hairdryer on a hot setting (little ones may need assistance here) – blow hot air directly onto the ink until it disappears. Other forms of heat will work as well – a hot radiator, an iron – but please be careful when handling extremely hot items!
3.
As the ink is thermochromic – intense heat will make it disappear! Now it is time to decorate your card..
4.
I have coloured in over the secret message – but don’t worry – it will still show through!
5.
Fold your masterpiece in half. Don’t forget to write the name of your Valentine inside it!
6.
Give your beautiful card to your Valentine and tell them to put the card into the freezer if they want to see the secret message….
The Magic!
The Science:
These erasable pens use a special thermochromic ink which becomes invisible when heated and reappears when chilled. The usual way of erasable the ink is by using the special ‘eraser’ on the end, which does not remove the ink, but generates heat by friction and causes the ink to disappear. This effect is reversed when the ink is exposed to cold temperatures which makes it perfect for our activity!
Affiliate Links:
You are welcome to use whichever erasable pens you wish – but here are affiliate links to some that we recommend:
- Set of 12 Legami erasable pens https://amzn.to/4rEwrEu
- Set of 5 Pilot Frixion pens https://amzn.to/3ZyrqkL
[Please note that as an Amazon Associate, I earn from qualifying purchases made from these links]