I need some recipes for making invisible ink with materials found in any house and how to make it appear?

Answer 1

Method One
The simplest method is to use lemon or onion juice to write with and let it dry. To reveal the writing, heat the paper with a iron, or other heat source.

Method Two
A more sophisticated approach uses an acid or base to write with and a pH indicator to reveal the writing. (pH is a measure of how acidic or alkaline a substance is - a pH of 1 is extremely acidic, 7 is neutral, and 14 is extremely alkaline). pH indicators change colour when mixed with acidic or alkaline substances.


To write with: White vinegar (which contains acetic acid) is probably the most convenient source of an acidic 'ink'. To make an alkaline 'ink' try a mixture of baking soda and water (around 50/50). With a small paint brush, write on a piece of paper using your chosen 'ink' and allow it to dry.


To reveal the writing:There is a natural pH indicator (a pigment called flavin) found in apple skin, grapes and red cabbage (amongst other things). Boil half a red cabbage in 5 cups of water. Filter out the cabbage, and spray or paint the juice over your invisible writing. I tried doing this with apple skin (I imagine this is only red apples), which also worked.


If you just want to see the pH indicator working, put a little of your cabbage/apple juice in the bottom of a glass and note the colour. Now add some white vinegar, noticing the colour change. Next add some baking soda. You will see the colour change back again. Enjoy :-)

Answer 2

Use lemon juice to write with and then to make it appear with the heat of a light bulb

Answer 3

Love it when someone actually knows what they are taking about. Go with Cindi, she did her homework and knows her stuff.