This study aimed to develop traditional costume content based on genre paintings from the late 18th-century Joseon period. By using Kim Hong-do's works as a foundation, this study creates a boy's first birthday outfit (dolbok) and explores the possibility of developing content based on historical records. The results of the study were as follows. First, this study proposed an 18th-century boy's dolbok consisting of a colorful vest (saekdong banbi), a small outer robe (sochangui), a jacket (jeogori), and pants (baji), departing from the 19th-century court costume dolbok form. It was produced in a form suitable for modern design based on historical verification by referring to costume relics and previous studies. Second, in order to produce four types of costumes, ancient documents, previous studies, excavated costume reports, and genre painting studies were comprehensively analyzed to determine the mesurements, colors, materials, and wearing methods so that they could be turned into costume content. Third, based on the results of these analyses, a boy's dolbok was produced. It was intended to produce it in a form close to 18th-century costume by realizing the composition and sewing methods of the 18th-century. This study expands costume history research by utilizing genre paintings as historical materials and presenting a process for developing precise traditional costume content. However, the potential for expressive distortion in genre paintings and the omission of certain accessories, such as the belt (doltti) and headdress (saekdong gulle), remain as limitations.