What is a fat face typeface? Imagine Bodoni gorged itself on donuts and candy for a month. A fat face typeface is simply an ultra-bold typeface, often with extreme thick-thin contrast. They were first used in the 1800s by British typographers on bills (or posters). At the start, they were often set in all caps. With time, italics and shaded versions gained popularity.
Some consider these slab serif typefaces. It depends on the design of the individual typeface.
Today, there are digital revivals of classic fat face designs.