Marvel Masterworks is an American collection of hardcover and trade paperback, full-color comic book reprints published by Marvel Comics, featuring various series in chronological order. The collection started in 1987 with volumes reprinting the first issues of The Amazing Spider-Man, The Fantastic Four, The X-Men, and The Avengers. Approximately 10 issues are reprinted in each volume, which as of 2008 number over 100 volumes. The line has expanded from such reprints of the 1960s period that fans and historians call the Silver Age of Comic Books to include the 1930s-1940s Golden Age; comics of Marvel's 1950s forerunner, Atlas Comics; and even some reprints from the 1970s period called the Bronze Age of Comic Books. There is also a black-and-white trade paperback line, Essential Marvel, with approximately 25 comics per volume, and the full-color, oversized, hardcover Omnibus line, each volume of which reprints the equivalent of three to four Masterworks.