In 1985-1986, DC published a series of comics called Who's Who: the Definitive Directory of the DC Universe. Each page had bios of characters, list of powers, etc. There was also new art commissioned for the series, often by artists associated with the characters. Here's a few examples from some of my favorite artists.
Dinosaur Island, by Bill Wray and Greg Theakston.
The Golden Gladiator, by Russ Heath.
Morgaine Le Fey, by Brian Bolland.
Nightmaster, by Charles Vess.