Microfilm, Microfiche, Micro-opaque
Mainly film in rolls. Occasionally available on microfiche (individual sheets of film). Rarely, historical content is available on now superseded opaque card stock (micro-opaque).
The New York Times, Chicago Tribune, Los Angeles Times; black and international newspapers at the Center for Research Libraries; Early American Newspapers; International Coalition on Newspapers (ICON) catalog.
Full runs of major U.S. newspapers in Olin; shorter runs of smaller newspapers. No color.
Historical completeness; original page format; very good preservation medium, easy to borrow from other libraries via ILL (esp. Center For Research Libraries).
Not current; lack of indexing; difficult to access (specialized machinery, localized physical access--not networked, but see ProQuest Digital Microfilm); some poor reproduction.
Invaluable for historians, historical research.