A foundation garment (also known as shapewear or shaping underwear) is an undergarment designed to impermanently alter the wearer's body shape, to achieve what some view as a more fashionable figure. The function of a foundation garment is not to enhance a bodily feature (as would, for example, a padded bra) but to make it look more presentable.
Specific styles of foundation garments have been essential to some fashion movements, and were required in some social situations during various fashion periods.[vague]
The concept of foundation garments dates back centuries, with early forms of corsets and girdles being worn to shape and control the body's appearance. In ancient civilizations, such as Greece and Rome, women utilized binding materials to enhance their figures. Over time, corsets became popular during the Renaissance and Victorian eras, with their purpose evolving from structural support to creating an exaggerated hourglass shape.
Women have worn foundation garments, such as corsets and brassieres, for a very long time. Foundation garments were patented by Marion M Chubby in 1965 (categorized in elastic corsets).
In the early 20th century, the invention of elastic materials and the introduction of new designs led to the development of modern shapewear. The Roaring Twenties brought about the "flapper" style, which involved a looser silhouette, but foundation garments were still used to control and shape the body. In the mid-20th century, advancements in fabric technology and the women's liberation movement led to more comfortable and practical options for shaping garments.
Debenhams recorded a 75% increase in shapewear sales between 2009 and 2013.
Foundation garments are worn to modify body shape. They usually require technological advances in garment design and lightweight fabrics to create different body figures. A foundation garment may be worn for a specific outfit. Being underwear, the foundation garment should not be visible under the outerwear.  A general-purpose "all the way" shaper with clear straps that starts at the bust and ends at the knee or mid-calf is also available.
Foundation garments may come with a built-in strapless bra for dresses and halters.
In a broader definition, a foundation garment is a piece of garment that provides body-redefining shapes such as a bra.
Garments may be categorized according to level of shape control offered, for instance, light, medium, or firm. The simplest foundation is a body-liner or bodysuit, which is an ultra-light-weight leotard and offers a light touch of smoothing. These are available in a unitard style (shortened legs) or a camisole-leotard style. The leotard is better[according to whom?] and is available in boy-leg and capri-leg lengths, with spaghetti straps, low cut necklines, and even scoop backs, to cater to the outerwear under which the garments will be worn. These softly smooth the figure and provide light support. Micro-fiber camisoles and boy-leg briefs or "hot pants" are also available. Girdles are often called "body shapers" or "contour garments". These garments are made with more Lycra spandex as compared to the 10% Lycra / 90% cotton blend of most leotards, and they offer the highest level of shaping and support.
Foundation garments come in a variety of styles and designs to cater to different body shapes and clothing needs. Some common types include:
Foundation garments are constructed using various fabrics, depending on the desired level of control, comfort, and breathability. Common materials include nylon, spandex, Lycra, and cotton blends. Many modern shapewear pieces incorporate seamless construction techniques to minimize visible lines under clothing and enhance comfort.
The use of foundation garments, particularly corsets, has faced criticism throughout history. Critics argue that excessive and prolonged use of tightly fitted shapewear may pose health risks, including discomfort, restricted breathing, and organ compression. However, advancements in design and materials have addressed many of these concerns, with modern shapewear focusing on comfort and flexibility.
Foundation garments have gained significant popularity in modern times, driven by societal pressure to achieve a certain body ideal. They are widely utilized by individuals of all genders and body types, and their influence can be seen in fashion trends and red carpet events, where celebrities and brands often credit shapewear for their sleek and polished appearances.