Many times writing invisible characters requires such reagents, and it is very troublesome to find materials. . Here are some simple ways to write invisible characters-

1. Lemon juice method

Ingredients: fresh lemon juice, pen, paper.

Pour the mixed solution of lemon juice and water into the pen, write on the paper, dry it and bake it on the desk lamp to make the words appear.

2. Starch method

Materials: dilute starch solution, iodine, paper, pen.

Write with a pen dipped in dilute starch solution, dry it and gently apply iodine, and the words will appear.

3. Milk Law

Materials: pure milk, pen, paper, water.

Write with a pen dipped in pure milk. When reading, put the paper in the water and you can see the words.

4. Running water writing method

Materials: a glass or mirror, a soft pen (just don't leave traces), water, and two sheets of paper that are not too thick.

Put a piece of paper in water on the glass, put another piece of Zhang Qian paper, write on the dry paper with a soft pen, and then put the dry paper

Take it down, and the soaked paper will appear when it is dried in water.