Print out a pumpkin template on watercolor paper. Or if you prefer, you can draw a pumpkin freehanded on a piece of watercolor paper. Scroll down past the tutorial for more information on the types of paper you can use.
Add the baking soda into a small bowl with water.
Stir well to mix the two.
Paint the entire pumpkin outline with the baking soda paste. Since we'll be cutting out the pumpkin when we're done, it's okay if you paint outside the lines.
Step 3: Add coloured vinegar and watch the reaction
In separate bowls, add the vinegar and 5 drops of each food colouring you'd like to use.We did one bowl of yellow and one of orange. If you don't have orange food colouring, combine equal drops of red and yellow to make orange.
Stir to combine the vinegar and food colouring.
Use an eye dropper to grab some of the coloured vinegar and add a drop or two at a time to the baking soda painted pumpkin.Watch the pumpkin begin to fizz!
Add more coloured vinegar and enjoy watching the bubbles and the colours spreading.
Continue adding both colours, watching the fun fizzy chemical reaction (more on that below!) and watching the colours combine.
Keep adding drops of colour until your entire pumpkin shape is coloured.
Step 4: Decorate your pumpkin (OPTIONAL)
Allow the fizzy pumpkin painting to dry overnight. If your artwork is feeling really 'sandy', you can rub the dry artwork gently with a dry cloth or paper towel to remove the baking soda texture.
Cut out the coloured pumpkin outline.
Add white glue to a googly eye.
Attach the googly eye to the pumpkin and repeat for the 2nd eye.We added googly eyes to our pumpkins, but you could also cut out a jack-o-lantern face from black construction paper!