Anamorphic writing is an application of perspective anamorphism, which means that an image can only be seen undeformed when viewed from a certain direction.
In this Demonstration, the image is a text message consisting of two perpendicular parts. You can switch parts by changing the orientation of the message.
The texts of the message are stretched vertically approximately 30 times. They are very hard to decipher from most view directions. The message can be read clearly when it is rotated to a very sharp angle (around 5°) with the view direction and preferably looked at with one eye closed.