The Unitard Defined
By definition a unitard is a full-body costume that covers the torso, legs, and feet. It may have a high or low neckline, and have any sleeve length. That is it may be longsleeve, shortsleeved, sleeveless, strapped, and although there is no definitional prohibition on it being strapless, its loss of utility makes this an unwitnessed silhouette. The strapped variety is also called a tank unitard, or a unitard tank.
Usually the unitard covers the feet, but it may leave the foot bare or it may have a strap underneath the sole of the foot and leave the toes and heels bare. Individual toes are rare. The sleeve length, neckline, and foot treatment provide for many variations. It can in theory also have fingers and cuffs and variations in fetish wear also include costumes with hoods. But that leads us to full-body bags, which is not our topic here.
Assuming the feet are uncovered a unitard has five edges; should the feet be covered it has three edges, and if the hands are also encased it has but one edge (the neckline).
Many users of language use the term "tights" or a "full-body leotard" to refer to what we here call unitard. So be advised. In Bikini Science tights are defined (constrained) to a waist-down garment that also encloses the feet. Tights are the bottom half of a unitard.
Topologically the unitard is a union of the leotard (a garment which bears the name of its inventor and which bares the legs, also called a maillot in swinwear parlance) and stockings. And especially with performers it may be hard to tell the difference (RS1650), especially if there is layering or seamstress work involved.
The Unitard is Invented
The unitard springs from an era of stage performance in which a flesh-colored body stocking provides an illusion of nudity. Flesh-colored unitards emerge in photography after 1900, when models and dancers are seen wearing them on postcards (PC0H01). In theater the flesh-colored unitard is an alternative to nudity; it possesses a resonance with tableau vivant (which is nude but motionless) because the unitard on stage is covered and moving.
In show business the pink body stocking or unitard is called just a pinkie. The slang is a very rich and loaded description. Professional unitards of the early 1900s are thin, flesh colored, and tend to cover the entire body with the exception of the face and hands. The unitards hug the body tightly, and display every curve and recess, but the performer is not nude. These sequences often augment the pinkie with jewelry, such as a necklace and bracelets, or a cape, which augment the effect and mutes the cheating (PC0HB0, PC0630).
Sometimes the pinkie is married to the act, such as in this faux nude faux wet bathing sequence (PC0H90).
As striptease gets developed in the 1920s the pinkie, also gets called the union suit, perhaps because it is requirement for working. The striptease is about singing and dancing and taking it off, and many an elaborate Victorian dishabille ends in a union suit. The body stocking tends to disappear after 1910, when toplessness and nudity emerge in the theater.
None the less, the pinkie remains in use up to the present for these same purposes; for example belly dancers spotted at a New York street fair performing with unitards underneath their dance costumes to dampen the effect of bare skin. And when the unitard reemerges in the 1990s exercise-wear craze, layering will also be one of its themes.
The Unitard Swimsuit
The creation of the unitard swimsuit in 1906 is told in detail in the Annette Kellerman story (AK0650, C1909A) and need not be repeated here. The short version is that Kellerman sews together a men's leotard and black hose to create her swimsuit breakthrough. Conversely a unitard is a bathing dress minus the dress.
Kellerman's "full body suit" on one hand appears additive, but in 1906 it is also subtractive, given that the more revealing beachwear of the day consists of a bathing dress over underwear and tights or stockings. So in this regard the unitard involves exfoliation--eliminating the bathing dress but maintaining a body covered by tight fitting fabric.
So once again, one of the latent themes in the early unitard is layering; more precisely, the unitard involves an unlayering action. Kellerman must be aware that her colleagues in theater are wearing body-fitting tights, and her focus on a black bathing unitard is a distinction from both the pinkie and the colorful maillot pantaloons seen in some pinups of the period and which she herself will help introduce to the beach.
For Kellerman, and the athletically minded, the unitard is a practical consideration that makes swimming less constrained, more practical, and safer.
If moralists are worried that the bathing unitard is more revealing and suggestive they are correct--especially when wet. And if they are worried that it is a step in a minimization direction, they are correct also. Because uncovering the feet and then baring the legs is an emerging battleground.
Keystone Girls and Others
Kellerman may introduce the unitard to the movies (AK0915), but the costume is quickly adopted by others during the early 1910s. These include fashion model turned movie star, Mable Norman, the first Keystone pinup girl, in the movie Water Nymph (MN1250). Ruth Rowland, still a starlet in 1913 does a similar unitard (RR1350) and will go onto a lasting career in the movie business. Musidora, the first vamp, wears a unitard that includes what appears to be a built-in head piece (MV1510). And unitards are a consistent costume for a bevy of swimming beauties who adorn a set of cards from Pan Handle Scrap chewing tobacco (PS1350).
Unitards will continue to worn by Hollywood sweethearts into the late 1910s (DB1650). That the unitard is the mid-point between the bathing dress sleeveless and the maillot is nowhere better illustrated than the evolution of the Keystone Bathing Girls themselves (KY1650).
The Modern Unitard
If indeed the unitard vanishes as the swimsuit reduces a twist of history revives it almost 100 years later--the fitness movement.
The modern unitard emerges in the early 1990s as exercise-wear acquires popularity as a specialized costume. Spandex is the driving material, so in this incarnation the unitard is tighter and stretcher than ever, worn with nothing underneath, sort of like a maillot with legs and usually sleeves. As with its original incarnations the variations include sleeve length, neckline, and the footed and strap variations. This sleeveless version has foot straps (KP88G3), this longsleeve version is footless (JE9208), and this fetish hooded version contains longsleeves, covered feet, and a hood--but also a navel cutout (T96A11).
The modern unitard is also brightly colored, a striking difference between the flesh-colored unitard of the stage performer or the black unitard of the Annette Kellerman suit. Frequently other garments are layered over top of, as if the athlete within wears only a culotte or tanga over top of their second skin (KP88G2). Sometimes the layered garment is for additional support, sometimes it is simply a colorful fashion statement. History repeats itself.