platinum age: 1930's similar to japanese manga, comic book sales declined

Golden age: 1930's to late 1940's. mainstream  art form, first comic superhero.

Silver age: 1950's to late 1960's, superhero comics were in decline, major commercial peak of comic industry kids were targeted more

Bronze Age:1970's boom in non super hero or boarder line hero comics, would address serious problems in society

Modern Age: mid 1980's to present, characters became darker and psychologically complex, creators became better known