あぶり出だし

noun, noun which may take the genitive case particle 'no'

invisible writing revealed by heat; writing in invisible ink

Refers to the technique or the resulting text; often used in the context of secret messages or children's experiments.

• 子こ供どもの頃ころ、レモン汁じるであぶり出だしをして遊あそんだ。

  When I was a child, I played with invisible writing using lemon juice.

• あぶり出だしの手て紙がみを火ひにかざすと文も字じが浮うかび上あがる。

  When you hold a letter written in invisible ink over a flame, the characters appear.