Published micropaleontological collections constitute a valuable geological heritage that contribute new data to science and the advancement of knowledge. The search for acquisition and archiving of such collections is the key to preserving this knowledge. The European Micropaleontological Reference Centre (EMRC) in Krakow collects and archives micropaleontological materials not only to preserve them, but also to make them available to the micropaleontological community for further research and education. The holdings mainly consists of tens of thousands of slides of foraminifera, as well as thin sections, documentation of materials in both archival and published form, and photographic data. These are physical data obtained from private collections, most of which have been the subject of published micropaleontological studies. Currently, the EMRC holds original collections from more than 250 publications, most of which were donated by researchers themselves or by their heirs. The collections have been catalogued, secured, and are stored together with the associated publications.