Rosa Sara (Ro) Keezer was a Dutch illustrator, book cover designer and painter. She was the daughter of Virginie Slijper and antique dealer Benjamin Keezer. Older brother Marcel Keezer (1903-1993) was active in the resistance in and around Leiden, bearer of the Resistance Commemoration Cross and employed in the art trade there. Older sister Els Keezer (1903-1943) was a dancer. Younger sister Hermine Jeannette (Toussie) Keezer (1912-2005), trained as an actress at drama school for only one year and was the first wife of architect Hein Salomonson. She married (with the glove) on December 9, 1936 with Judah Harrison and then left for the then Dutch East Indies where she became a widow three years later. In 1949 she remarried with Robert Herhard Hermann Steinberg, which was followed by a divorce in 1955. Keezer was educated in Paris and had exhibitions in the late 1920s. She also lived in Paris. For example, she provided illustrations for Edition Nilsson. In 1933 she illustrated Wending by Emmy Belinfante (Valkhoff & Co). In 1942 she taught at the Secondary Jewish Arts and Crafts School WA van Leer at the Hollandsche Schouwburg and at Kloveniersburgwal 15. She also designed illustrations for publishers such as Noordhoff , HJ Paris, Mulder & Co, Valkhoff & Co, Joachimstal and FG Kroonder. She also worked as a book cover designer . She made a separate booklet, Dutch costumes and old poems, for the fashion house Maison de Bonneterie, with 25 full-page illustrations.