Invisible-ink sentence example

invisible-ink
  • He sent messages written in invisible ink on sheets of music.
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  • In this section, we'll show you how it's been used and tell you how you can make your own invisible ink.
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  • It is tough to be a good spy when you can find your invisible ink pen but not your list of secret codes.
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  • This includes a cipher wheel, an invisible ink writer and a flashlight created for use with Morse code.
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