INVISIBLE INK EXPERIMENT

• There are at least two methods to use baking soda as an invisible ink. Mix equal parts water and baking soda.

• Use a cotton swab, toothpick, or paintbrush to write a message onto white paper, using the baking soda solution as 'ink'.

• Allow the ink to dry.

• One way to read the message is to hold the paper up to a heat source, such as a light bulb. The baking soda will cause the writing in the paper to turn brown.

• A second method to read the message is to paint over the paper with purple grape juice. The message will appear in a different color.