How to Make Invisible Ink with Lemon Juice

I have been wanting to try invisible writing with lemon juice for awhile now, but we haven’t gotten around to it.

We were sent a copy of  Tinkerlab: A Hands-On Guide for Little Inventors (affiliate link) written by Rachelle of Tinkerlab and when my preschooler saw it in there and asked to try it I immediately said yes!

Invisible Ink with Lemon Juice

• lemon juice (any citrus will work)
• cotton swabs
• cardstock
• iron

I love simple activities and this one is perfect! All you need to create invisible ink is lemon (or lime) juice and a heat source.  We followed Rachelle’s suggestions to use cotton swabs and cardstock and it worked perfectly.

My daughter and I each dipped the cotton swabs in the lemon juice and wrote secret messages on the cardstock. Once they were dry I ironed them to make the messages appear.

I set the iron to the cotton setting and put a kitchen towel under the paper and ironed right on the cardstock. The heat broke down the acid in the juice and the message appeared!

Invisible writing is such a great way to add a little science (and magic!) into writing. You can use invisible writing to get kids excited about handwriting, practice math facts and create art that appears on the page.

Tinkerlab: A Hands-On Guide for Little Inventors is more than just a book filled with fun art or science projects–it truly is a guide for parents and educators of young children. The child-led focus and the interviews with experts from so many fields have me reading and re-reading sections to just soak it all in.

My kids have expressed that, “the projects are so amazing!” and love to sit and flip through it looking for inspiration. We highly recommend it!

Disclosure: I was sent a free copy of this book but they in no other way sponsored this post. All opinions are mine (and my kids’) alone.