This non-toxic chalk made using eggshells is one of my favorite things to make. It’s a great way to repurpose eggshells and you can use ingredients from your pantry as natural dye pigments. There’s also the option to substitute calcium carbonate powder to create a finer chalk. Both of these chalks perform similarly but the eggshell chalk will be grittier and more abrasive depending on how much you are able to grind them up. You can choose to use either or both, and there’s a photo with a comparison below. In general, this chalk is very abrasive it would work best outside on sidewalks. I’ve had good luck making several batches that DO work on our slate chalkboards (like in the photo below of my four year old’s snail drawings) by using the calcium carbonate powder. I don’t advise testing the chalk on anything that can be being scratched and damaged, since it is very abrasive.

Materials:

– calcium carbonate or eggshells (powdered, see directions below)
– flour
– natural pigments for natural dye (In this tutorial I used turmeric, paprika, beet root powder and cocoa. Matcha powder and butterfly pea powder are also lovely options)

Step 1: How to make eggshell powder (optional)

If you are using eggshells: Empty shells out completely and rinse well with hot water, also removing the inner membrane. Boil for 5 minutes to kill off any potential bacteria and make sure your egg shells dry completely. Grind your eggshells into a fine powder using a mortar and pestle or the back of a spoon.

Step 2: Mixing the chalk

In a small bowl, combine 1 teaspoon of your natural pigment/dye material (I’m using what I currently have in my pantry which is turmeric, paprika, beet root powder and cocoa) with 2 teaspoons of hot water. Stir to combine. Add 1 tablespoon of flour and 1 tablespoon eggshell powder or calcium carbonate. The mixture will seem dry and clumpy at this point.

Step 3: Forming the chalk

Use your hands to mix and knead the mixture until it is smooth and combined. Add small amounts of water at a time if necessary so that the mixture sticks together (add slowly— you want to add as little water as possible). Roll the mixture out to shape and form sticks. I *think* you should also be able to press the mixture into a silicone mold to create shapes instead of rolling them into sticks but I have not personally tried it myself. Allow to dry completely for at least 2-3 days on a piece of kraft paper, parchment paper or on a towel. Comparison photo of turmeric chalk below using eggshell powder (top) and calcium carbonate (bottom). Let dry completely, then use to draw on any outdoor sidewalks or pavement!

Note: This DIY chalk recipe contains eggs and wheat. If you plan to give these away or to make them with children, please be aware of any possible allergens.