There were thirty-two lid designs tested in the study, including two diameters (28 mm and 42 mm), two heights (9 mm and 17 mm), two top shapes (circular and hexagonal), two side shapes (flat and convex), and two surface texture of sides (smooth and serrate). The selections of lid shapes and surface texture tested in the study were based on results from Yen et al. (2013). Heights and diameters represented smaller and medium sizes of common beverage bottles, water bottles, and sauce/dressing containers currently in the market. Images and dimensional information are provided in Table 2. The lids were made using a 3D CAD/rapid prototyping system; they were all white plastic and were attached to identical bottles in order to minimize any subjective preference based on appearance.