“The use of revealing costumes does, however, present Bill [Theiss] with some structural engineering problems. Breasts are the main problem. In terms of Star Trek costume design, there are three kinds of breasts: no breasts at all (great), good breasts that are firm and need no support (rare), and the vast majority (terrible). Large or small, the vast majority need support, and in costume design that can be a disaster.Stephen E. Whitfield, The Making of Star Trek (1968)
In order to achieve a fresh look through the use of nudity in unexpected places, the bra must often be dispensed with. This of necessity dictates a girl whose breasts do not need support…
Small breasts are, therefore, far and away the best and easiest to work with. If more “volume” is required, falsies can be sewn into the costume or, as is often done, simply glued right to the breast.”
Lesson: The women being costumed are the issue, never the expectations for the costumes.