Valentine’s Cards: Coded Message


Today we have a fantastic Valentine’s Day Science Activities by the wonderful Trisha joining us from Inspiration Laboratories on our 31 Days of Love and sharing her science-y Valentine Cards for Kids – can you crack the code?! We also have some great Valentine Crafts for Preschoolers, Valentine Day Treats and Valentine Decorations projects for you to browse!

Secret Code Cards

Hi! I’m Trisha from Inspiration Laboratories, and I’m happy to be sharing our secret code card with you today. We combined art and science {one of our favorite things to do} to make a pretty Valentine’s Day card and placed a secrete code message on the inside.

Valentine’s Card for Kids: Secret Codes

Here are the supplies you’ll need:

  • card stock
  • watercolor paper
  • liquid water colors {and/or watercolor paint}
  • paint brushes
  • salt {regular table salt or kosher salt}
  • crayons
  • scissors
  • glue {we used glue stick}
  • printed {or written} secret code messages

Create Your Valentine’s Card

  1. Cut a piece of card stock to the double size card you like and fold in half. {You can also buy blank cards.}
  2. Cut a piece of watercolor paper about an inch or two smaller than the front of your card.
  3. Write or draw a message onto the watercolor paper with the crayon color of your choice. {I chose a bright pink crayon.}
  4. Paint the watercolor paper with watercolors of your choice {to compliment the crayon color}. We tried both liquid watercolors and regular {dried} watercolor paint. The liquid watercolors were more vibrant, but the regular watercolor paint worked okay with some of the colors – pink, red, and orange turned out well. Just make sure you use plenty of paint if you use the dried watercolors.
  5. Sprinkle salt onto the watercolor paper. Using different size grains of salt will produce different effects. We used table salt {fairly small grain} and kosher salt {a larger grain}. The salt absorbs water from the paper.
    salt and watercolor
  6. Let your art dry.
  7. Wipe off the salt from your paper.
  8. Glue the paper to the front of your card. {It may help to place your card under a stack of books if your paper is curling.}

Here are 2 of our finished cards. The pink one was painted with regular {dried} watercolor paint.

watercolor card2

The blue one was painted first with pink regular {dried} watercolor paint and then with turquoise liquid watercolors.

watercolor card1

The Science Lesson

What causes the snow-like or sparkly effect? Where the salt touches the paper, it absorbs water {and paint}. This cause the color to be lighter where the salt is. For younger children, discussing how salt absorbs water is probably sufficient. For older children, you could begin to talk about osmosis – how water moves across a membrane to where there is a greater solute {salt} concentration. You could use this art project as a jumping off point for osmosis experiments.

Add a Secret Code Message

There are many ways to create a secret code. Discuss options with your child and have fun making one. We used a simple substitution cipher where one letter is represented by a number. Place the secret message inside your card, and include the secret code so your message can be read. Our messages said Happy Valentines Day, I Love You, and Be My Valentine!

secret code

More Secret Message and Valentine Ideas for Kids

Secret Messages with Baking Soda Secret Message Art Frozen Vinegar

Create secret messages with baking soda and a special liquid.
Make secret message art with glue and paint.
Try some Valentine science with frozen vinegar hearts.
Experiment with candy hearts and discover which ingredient reacts with baking soda.

Thanks for letting me share with you today!

TrishaTrisha is a stay at home mom to her 4-year old son, Aiden. She writes about their adventures at Inspiration Laboratories, a blog dedicated to encouraging learning through creativity and play. Trisha is an educator with a passion for science literacy. It is never too early to start encouraging science learning (or any kind of learning for that matter). Follow along on Facebook, Twitter, Google+, and Pinterest.

Fancy some more Valentine’s Day Science Ideas? Take a look at these easy to do and implement projects! LOVE:

STEAM Valentines Activities

Nurturing Little Thinkers! Hope these Valentine’s STEAM Activities inspire you to have a go!

We have LOTS more Valentine Cards for Kids for you to browse as well!


Happy Valentines Day!!!!!