Secret Father’s Day messages

KeithL composing his invisible Father's Day message.

In our Intermediate English Fun class, we’ve been reading one of Michele Torrey’s excellent Doyle & Fossey: Science Detectives books, The Case of the Mossy Lake Monster.

RachelL composing her invisible Father's Day message and, at right, what she wrote.

The second story in the book begins with Drake Doyle removing a seemingly blank sheet of paper from a pouch hanging around the neck of Dr. Livingston, Nell Fossey’s dog. Nell, a young naturalist and Doyle’s partner in their science detective agency, has sent Drake a message via her pooch, but he has to switch of the lights in his laboratory and hold the paper under a UV lamp (also commonly referred to as a black light) to read what she’s written.

JasmineL composing her invisible Father's Day message and, at left, what she wrote.

At the end of the book, the author explains how children can compose their own secret, UV-visible messages on white paper using sunscreen lotion as the ink! This technique relies on the fact that sheets of white paper contain brighteners that cause them to glow under UV light. The sunscreen will block the UV, so the letters you’ve written will appear as dark lines against a black background.

LocaniW composing her invisible Father's Day message and, at right, what she wrote.

For our in-class activity this past weekend, we gave each of the students a combination fluorescent pen and blacklight and sheets of cute, cartoon-character-themed stationary and asked them to compose Father’s Day messages for their dads. The effect is the inverse of that described in the story since the ink is fluorescent and will appear brighter than the background — especially on paper that isn’t bright white, like the stationary that we used.

Pictured in this post, from top to bottom, are four of our students working on their heartfelt Father’s Day messages: KeithL, RachelL, JasmineL, and LocaniW.