Alexander F. Remington and Michael Cavna, writing for The Washington Post:
Traditionally, comics were drawn from a screenplay-like script
provided by the writer. Instead, Mr. Lee said, he would offer his
artists plot ideas and brainstorm with them. The artists would
then draw the story, and he would later fill in dialogue and text.
Artists in his “bullpen,” where the artists worked in proximity to
each other and to him, were much more involved in the creative
process. This became known as the Marvel Method.