Happy Valentine’s Day love-lovers! This year, we made a set of artful cards featuring my own love language – geometric shapes. But hidden in plain sight is a mystery for little visual detectives to solve….can you crack the code??

Send handmade art with a secret message this Valentine's Day! A wonderful activity for kids with printable morse code and nautical flag printable templates available. | via barley & birch

Using Morse code and simple art-making processes, this super fun project doubles as an experiment in visual languages. An activity for both the card-maker and the recipient, this is truly the valentine’s day greeting that keeps on giving!

Whether you download our alphabet kit or use the reference pictures to draw, cut out, or stamp your own, this is guaranteed to delight code-cracking sleuths of all ages.

Make coded secret messages with our morse code and nautical flag alphabet printables! | via barley & birch

Making these cards took me right back to one of my favorite reading memories – a picture book by Graeme Base called The Eleventh Hour. The illustrations were absolutely stunning, and among all of the luscious details were hidden clues to help the reader solve the mystery at the center of the story. My sister and I poured over the book for days trying to crack the codes.


Much like that book, these cards present a fun little mystery to be solved beyond looking lovely. And there’s something else hiding in this project too – a fantastic experience in playing with language, communication, and alphabets. Check out our DIY secret message cardboard sailboats to put the nautical flags to use too!

Is your kiddo stoked about secret codes? You may want to try this unique character alphabet activity or sharing their message with chalk spray paint next.

To make your own secret message Valentine art you’ll need:

BASIC SUPPLIES:

  • A few sheets of construction paper or cardstock in an assortment of colors
  • Scissors
  • A glue stick or craft glue

OPTIONAL SUPPLIES:

OPTIONAL STAMPING SUPPLIES:

  • Paint or a stamp pad
  • Recycled items (like bottle caps) potatoes, or scrap cardboard to use as stamps
  • Two pencils with erasers for small DIY morse code stamps

Morse Code Valentine Art Instructions:

Print the Morse code and nautical flag alphabet references.

You can download and print our handy secret message printable pack or google reference pages to use for coding your own secret messages.
Secret Message Alphabet Sets Printable Preview

Write out your message in code on scrap paper.

Before you start making your art, write out the morse code message you want to send in scrap paper, or cut out the flag letters you’ll need from our nautical flag alphabet set and arrange them in order. For our Valentine’s Day cards, we chose to write “LOVE” and “I LOVE U” in morse code. We wrote out “I LOVE YOU” in nautical flags.

This will allow you to see how you’d like to lay out the message on your card. You can make it BIG as we did for our “LOVE” morse code card, or write a longer message small, as we did with our “I LOVE U” (repeated) for our heart morse code card).

Make simple arrangements using construction paper or stamps.

For our “LOVE” card, we cut 1.5-inch squares from construction paper and made a 4×4 grid on a piece of cardstock. We glued our grid down, then trimmed the excess cardstock.

Instead of using scrap paper, you could also make this with stamps – keep reading to see how we made our own stamps out of recycled household supplies.

Tip: For easy equally-sized squares, you can trace around a wooden play block as we did!

Add your Morse code or nautical flags.

You can cut scraps of paper to create the simple shapes for your morse code, stamp them out, use office label stickers, or simply write out your message with a pen, marker, or crayons.

For the nautical flags, you can cut out letters from our alphabet sheets, or draw your own. If you’d like to create small banners as we did, leave a tab of white above your flags when you cut them out. You can fold this tab around a piece of ribbon or yarn and glue to create a 3D flag!

Add details.

Because our art doubles as Valentine’s Day cards we cut out hearts to add to each one, using a glue stick to glue them on. They look SO sweet, but the practical reason for adding these hearts is so your recipient will know which way is up and be able to decode your message.

Print out or draw your own decoder sheet.

Once you’ve finished your card, print out or draw a decoder sheet to fold up and send along with it to help your valentine crack the code!

The geometric style of these cards and alphabets presents a unique opportunity to try this in a variety of mediums. Using the composition of our “LOVE” Morse code card, we collected a variety of household supplies and recreated it through stamping.

Stamped secret messages using wooden blocks and recycled household supplies. | via barley & birch

A wooden block made our grid squares, and we were able to use the glue stick cap and a small plastic candy box to stamp the shapes creating our morse code.

Or, instead of stamping, you could use round color coding stickers/rectangular office labels – or simply draw your Morse code message. Playing with the materials you have around you is half the fun of this coding project!

More Ways to Play with Morse Code

While doing research for this post, I found so many incredibly creative Morse code activities. Here are just a few you can use with this project to add context or build on the lesson…

  • Instead of writing your messages out, use flashlights to spell the words. There are quite a few Morse code apps like this reader and decoder that can use your phone’s flashlight.
  • Try making some Morse code music.
  • Set up a Morse code treasure hunt – your little ones can pretend they’re on a secret mission!
  • Make a set of Morse code bracelets and swap secret messages with friends.
  • Older kids ready for more advanced STEM projects can try building this DIY Morse code transmitter.
  • As part of a series highlighting accessible communication, Google has curated a series of free learning games your kids can play on phones or tablets using a free downloadable keyboard language.

OR move beyond Morse code…this fantastic collection of secret codes features 5 cool “secret” languages that are guaranteed to appeal to young curious coders.

Send handmade art with a secret message this Valentine's Day! A wonderful activity for kids with printable morse code and nautical flag printable templates available. | via barley & birch

For more handmade valentine card projects, try making your own mixed media heart bouquet cards, or send your message of love via (paper!) messenger pigeon.

For sugar-free entertainment, try these poseable conversation hearts, create wearable art with our heart pennant pin DIY, or build a STEAM-powered cardboard love shack.


*A note about affiliate links: We strive to use simple, earth-friendly supplies that can be purchased locally whenever we can, but sometimes we find the best universally available options, a rare eco-friendly find, or a niche product only available on Blick Art Materials, Amazon, Etsy, or Woodpeckers Crafts. When included in our supply list, these products are affiliate links, and if you click through to make a purchase we receive a small commission that helps us re-order these supplies!

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Amanda Eldridge
Amanda Eldridge

With a passion for cultivating imagination, Amanda aims to help kids and families discover their creative potential through art, play, adventure, activism, conservancy, and community. Amanda has a background in graphic design, environmental design, and art curation. When not playing with ideas and designs for barley & birch, she enjoys working in freelance design, art, and illustration.

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