Personal collection of the sculptor and collector Frederic Marès i Deulovol (Portbou, 1893 - Barcelona, ​​1991). Considered the original nucleus of all the documentary materials of the Frederic Marès Museum, and at the same time the most extensive and diverse. It includes documents dated between the 12th and 19th centuries, although the majority of documentation corresponds to the period 1893-1991. Contains the personal correspondence of Frederic Marès , as well as personal and family documentation, school and training, of his professional activity and his sculptural work. 

It also includes some personal funds, such as that of the writer and cartoonist Eveli Bulbena (1888-1960) and the playwright and journalist Conrad Roure (1841-1928). It also consists of documentation from some institutions such as the Royal Catalan Academy of Fine Arts of Sant Jordi de Barcelona, ​​the Royal Academy of Fine Arts of San Fernando, the Academia del Faro de San Cristobal de Vilanova i la Geltrú, the School of Fine Arts, the School of Arts and Crafts, the Board of Museums of Catalonia, the Royal Artistic Circle... It also contains handwritten documentation on paper and parchments that span from the 14th to the 19th century.

The collection was preserved by Frederic Marès until the year of his death, in 1991. From 1996, when his Study-Library was opened to the public, the documentation was moved to the Museum's internal services space, located on the basement floor, where the Documentation and Research Center is currently located.

The Documentation and Research Center has completed part of the digitization project frederic Marès personal fund and presents the online catalog with more than 400 letters of the correspondence received from Frederic Marès with the institutions.