The 1940s was the era when the midriff was born, and it was shown in swimsuits as well as playsuits. 1940s swimsuits were tight, unlike the suits of previous era.
One-piece swimsuits were still popular, but the new two-piece suit had plenty of fans too. The materials used to make swimsuits our of rayon jersey and rayon jersey blends with knit cotton linings. Many suits had accent panels of a velvet like rayon velour. Some also featured ruching on the front or side panels that were both pretty and figure flattering.
1940s One Piece Swimsuit
The one-piece swimsuit looked like a very tight, short dress. The bra top resembled a full-coverage bra. The suit then extended down into a tight ‘skirt’ that would cover the backside completely. Skirts were either snug fitting around the hips and thighs or loose, called “swing skirts.”
The back of the suit would be even with the under bust line. Some zipped all the way up the back for full coverage while others tied the bra top around the back leaving a gap between the bra and the bathing suit waist. The one-piece offered plenty of shaping, and sometimes had boning in the stomach area to offer additional support. A halter top was also popular — the suit would look the same except the straps tied at the neck. A new feature of some one-pieces bared a little bit of skin — a small triangle of fabric would be cut out underneath the bust to show some skin (but always above the naval.)
1940s Bikini or Two Piece Bathing Suit
The bikini was officially invented in 1946 and named after the Bikini Atoll in the south Pacific where the U.S. performed nuclear tests. This suit was tiny, revealing the belly button and buttox. Most public beaches banned the use of this new tiny swimsuit till the ’50s. However, this wasn’t the style of two-piece that was usually worn in the ’40s — it was a little bit too revealing.
Before the bikini, women started wearing two-piece swimsuits that looked just like one-piece bathing suits cut in half. The top was a full-coverage bra top, either with two thin straps or a halter top. The bottom looked like a tight mini-skirt, starting from the waistline and covering the entire backside. Another popular style of skirt for the two-piece was a flared skirt bottom of the same length. A top that started to gain in popularity was even more revealing — a bandeau top with strings attached to the center front that tied at the neck.
By the late 1940s, one and two piece swimsuits were losing even more modesty. The strapless two piece was especially popular to those brave enough to wear them. By the 1950s nearly all swimsuits were strapless. More boning and lastix was needed to keep their shape and hold the girls in place. Needless to say vintage swimsuits of the ’40s and ’50s were hardly used for vigorous swimming. A lazy day at the beach or pool was their best use.