Due to censorship statutes, the Poster Collection contains only few posters printed before the Finnish independence. The collection started growing fast in the early-1900s. Important sub-collections include film posters from 1920s to 1980s. political posters especially from 1907–1944, posters advertising entertainment and other events as well as products advertisements.
The collection grows by approximately 2,000 posters each year. Significant donations include the Year's Best posters 1967–1977 received as slides as well as slides of large outside posters for 1982–1987.