Write a Love Letter with a Hidden Message

I was looking though boxes of old stuff and found this love letter I wrote my husband years ago.  It was actually a book that I made him (hand bound and everything) for Valentine's Day that was filled with lyrics to our favorite songs and at the end I wrote him a love letter with a hidden message.  The hidden message in the letter was "I want you for always, days, years, eternities."

To make this hidden message letter, I first came up with the message and then wrote a letter that contained those words.  It wasn't that difficult because those are words I are typically written in love letters.  After writing the letter I printed it on a sheet of transparency paper (blanking out the words "I want you for always, days, years, eternities - to do this in MS Word just change the words to white text color).  Then I printed another copy of the letter on white paper, with only the message showing (again just changing the text of the letter to white color).  It was actually a Valentine's gift that my husband was impressed with.

When looking at the letter you can't tell that there is a hidden message.  Only when you flip the transparency over will it reveal the message.

I also made him a CD with our favorite songs and put our faces as the custom cover.  This was super easy to do in Photoshop.  Do people even listen to CD's anymore?  I am so out of the loop.  I still have a cassette player in my car.