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Western dress codes and corresponding attires
Formal (full dress)   White tie  Morning dress  Full dress uniform Frock coat  Evening gown  Ball gown
Semi-formal (half dress)   Black tie  Black lounge suit   Mess dress uniform Evening gown  Cocktail dress
Informal (undress, "dress clothes") Suit  Service dress uniform Cocktail dress  Pantsuit
Casual (anything not above) Business casual Casual Friday Combat uniform Smart casual Workwear Streetwear Sportswear known as Sportswear (fashion) and Athleisure Undress
Supplementary alternatives Ceremonial dress law courts royal courts diplomatic academic, etc. Religious clothing cassock, habit, etc. Folk costume Distinctions Orders medals, etc.
Legend: = Day (before 6 p.m.) = Evening (after 6 p.m.)     = Bow tie colour = Ladies = Gentlemen  Fashion portal  Contents/Culture and the arts portal
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Formal trousers, also known as formal striped trousers or colloquially spongebag trousers, are grey striped or patterned formal trousers for day attire in traditional Western dress code, primarily associated with formal morning dress or secondly its semi-formal equivalent black lounge suit.^[1] Traditionally made from heavy wool ranging from worsted, melton to partial twill weave, the pattern is most often of a muted design in stripes of black, silver, white and charcoal grey in various combinations (not to be confused with pinstripe or chalkstripe, which are formed of single thin lines spaced equally apart). In addition, formal trousers may also come in check patterns, such as houndstooth check, or plaids, although these variants are widely considered as not the most formal.

Typically, formal trousers are intended to be worn with braces with a fishtail back covered by a waistcoat, and have pleats for correct ironing result and comfort. Likewise, for traditional reasons of formality, they do not have turn-ups, since these are considered less formal.

Name

The British synonym "cashmere striped trousers" refers to the actual name of the stripe pattern, and not to the fabric. Similarly, the slang term "spongebag trousers" or "spongebags" is due to the perceived similarity of the distinctive stripe pattern to traditional sponge-bags, a bag of toiletries (but does not apply to check patterns). In Germany, the synonym "Stresemann trousers" occurs, for the same reasons as the semi-formal stroller is called a "Stresemann".

History

Formal trousers were originally introduced in the first half of the 19th century as a complement to the then widely worn frock coat. As established formal day attire trousers, they were subsequently introduced to go with the morning dress, which in turn gradually replaced the frock coat as formal day attire standard by 20th century, along with its semi-formal equivalent black lounge suit.

Gallery

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  Different innovative, early interpretations of formal trousers with frock coats and top hats, in Stockholms mode-journal (1847).
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  Edwardian era-styled morning coat with formal striped trousers (Fashion, 1901).
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  Brazilian President Washington Luís during a military ceremony (late 1920s−early 1930s).
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  Sir John Goodwin and Lady Goodwin together with Neil Campbell and his wife, walking over the Grey Street Bridge in morning dress, top hats and spats (1931).
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  U.K. Prime Minister Winston Churchill in a black lounge suit with homburg hat and walking stick on Downing Street, giving his famous 'V' sign during World War II.
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  Former U.S. President Harry Truman with William Lyon Mackenzie King (1947).
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  Prince Philip consort of Queen Elizabeth II of the United Kingdom (1951)
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  John F. Kennedy and Jacqueline Bouvier Kennedy, in wedding attire, outdoors (1953)
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  Patrick Moenaert, Mayor of Bruges (left), and Paul Breyne, Governor of Western Flanders (right), both in morning dress along with formal trousers at the Sanguis procession in Bruges, Belgium.
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  Formal trousers to a black lounge suit in an exhibition of the Textilfabrik Cromford, Ratingen, Germany.