The person receiving the letter – or party invitation – simply irons the paper to reveal the message. This activity is perfect for an adventure party. You can even get tricky and make the invisible ink message more fun to read by writing in normal pen and then asking the recipient to iron the message to reveal the party details.

To make invisible ink, you’ll need:

• Blank paper
• Lemons
• Cotton tips or a small paintbrush
• A bottle
• Matches (optional)
• Small cup or bowl

How to create an invisible ink birthday party invitation:

• Cut and squeeze the lemon into the small bowl
• Use your paintbrush or cotton tip to write the message or draw a picture. If you look at the page on an angle in certain light you’ll be able to see what you’re writing or drawing (a bit!).
• Wait for the lemon juice to dry, then have an adult gently “burn” the edges of the paper to age it. Just hold the paper near the flame and it should brown. Do so right near a kitchen sink in case it catches fire!!
• Roll up and place in a bottle. Attach a note for the recipient so they know they have to iron the paper for the message or image to reveal itself.