The Donald B. Croly Boeing Concept Art Collection holds 39 pieces of concept art created by Croly, circa 1940s-1970s, during his time as an artist at the Boeing Company. Most are original gouache paintings, although there are three pen and ink and graphite drawings and two photographic reproduction posters. Scenes primarily depict aircraft in a variety of settings, including in flight, parked at terminals and engaged in U.S. Air Force military operations. A small number feature loading/unloading of passengers, cargo or military equipment and passenger seating. Most are unsigned but a number do have Croly's name evident on the front. Very few have contextual information, such as the date or aircraft model.

Identified aircraft include the Boeing CIM-10 Bomarc, Boeing Model 247, Boeing Model 733 SST, Boeing 7X7 series, Boeing Model 2707 SST, and the Ryan M-1. Many are unidentified due to their conceptual nature. There is one non-aircraft painting that features the 1919 Boeing "Sea Sled" boat. An undated booklet of Boeing artist biography briefs is also present.