This is a quite creative use of modern printing techniques by Mathias Nösel and Matthäus Frost. This annual report appears blank when you are indoors, but reveals the content when you get some sunlight.
I just wish they would have given more information on the techniques used to achieve this result.
About the Author
Mirko Humbert
Mirko Humbert is the editor-in-chief and main author of Designer Daily and Typography Daily. He is also a graphic designer and the founder of WP Expert.