The 1940s were a relatively quiet decade for hockey cards. World War II significantly limited card production. The oversized 1940 O-Pee-Chee set introduced a new generation of NHL goalie rookies, including Johnny Mowers and Paul Goodman. Card production during the decade was generally modest, featuring simple designs, muted colours, and lower-quality paper stock. As a result, many surviving cards display worn corners and other signs of heavy handling. For collectors today, high-grade examples are especially prized—not necessarily because of the star power of the featured goalies, but because well-preserved copies are exceptionally scarce