Methodology was developed to measure six persistent features (décolletage width, décolletage length, waist width, waist length, skirt width and skirt length) of evening dresses, 1920-1980, from two university costume collections. Garments fit onto dress forms were photographed. Metric measurements were made directly on the photographs. Aesthetic rules derived from Greek ideals found in apparel design texts were tested by considering proportionate relationships between pairs of dress dimensions. Differences between university collections existed but were overshadowed by similarities in proportionate relationships. Data from both collections were combined and compared to findings utilizing magazine data from the same time period. Regardless of data source, designers follow similar aesthetic rules, but not necessarily those found in apparel design texts.Using pictures in fashion magazines to study changes in women's dress over time has a well-established record. Kroeber (1919) pioneered in this regard, utilizing fashion plates from the Petit Courrier des Dames, Harper's Bazaar (then Bazar), and Vogue to study persistent features of women's formal evening dress (width and length of d6colletage, waist, and skirt) from 1844 to 1919. Young (1937) used the Delineator, Good Housekeeping, and McCall's to examine skirt silhouettes for day wear. In 1940, Richardson and Kroeber expanded Kroeber's (1919) data base, back to 1605 (utilizing broken sets of fashion illustrations and engravings) and forward to 1936 (utilizing Vogue, Harper's Bazaar, and Costume Royal). Recent researchers have continued to study fashion change as represented in fashion publications (Behling