The Boldt Collection comprises over 1,500 interior design, applied, and fine arts materials that are international in scope and span from ancient times through to the 1980s. The collection includes plans, blueprints, drawings, paintings, and models. Many of the framed pieces from this collection are displayed throughout the Reinsch Library building.
The collection contains materials originally housed in the International Institute of Interior Design Library. Founded in 1957, and presided over for three decades by Mabelle Wilhelmina Boldt, the Institute provided professional training to students in interior design. The Institute ceased operation in 1990.