A demotivational poster or picture is an image that is made up of a picture bordered in black and accompanied by a subject title and, in most cases, a tagline. While intended to dishearten the reader of his moral strength and self-esteem, demotivators are actually a good resource of Internet humor.
The meme is generally attributed to Despair Inc, a Texas company that makes a satire of motivational posters (usually found in large corporations and offices as sources of work inspiration) since 1998. The merchandise by the company has spread widely all throughout online forums and blogs. They even provide a do-it-yourself tool for anyone interested to create their own posters.
The thick black border comprises around 20 to 40 percent of the whole image. The central picture usually offers comic relief and is the focal point of the image. To complement it, a title is added below, usually white and in all caps. The tagline or caption, in smaller font, will often avoid mentioning the nature of the central picture but rather give a misleading reference.
Over time, however, demotivationals have been simplified into memes. They are no longer restricted to satirising corporate and educational themes. Crude and bizzare images are commonly used these days with simpler, yet still funny, captions.
To help Redditors, the Demotivational subreddit has a straightforward guide on how to make a good poster:
Pretty, uplifting picture
A line that does not inspire and is ideally funny