How to Make Ink Appear
- 1). Iron the paper on a low heat setting if the message is written in lemon or onion juice. Adjust the heat higher in increments if you can't see the message.
- 2). Make an indicator if the letter is written with an acidic or alkaline ink. An acidic ink would be white vinegar; an alkaline ink would be a mixture of baking soda and water. The indicator will react with these substances and cause them to show up.
- 3). According to Kid Craft Central, you can make your own indicator by boiling the leaves of half a cabbage in 5 cups of water.
- 4). Dip a paintbrush into your indicator and paint over the message. The indicator will react with the writing and make it visible.
