Cocktail attire indicates that an event's dress code is between black tie and casual. Traditionally, cocktail attire requires dresses to be knee-length, but as of 2014, the fashion allows hemlines to rise. Dresses should be made out of silk or crepe, with an eye towards seasonal appropriateness. For example, cocktail dresses worn for winter can be made of wool blends, while those for the spring and summer can be made out of satin.
Cocktail parties also have different levels of formality, which can be inferred by the type of invitation received. Invitations that arrive through phone or by email indicate a more casual atmosphere, while invitations that come via more formal venues require more dressy attire.
Cocktail parties started gaining popularity during the '20s, as occasions where hosts invited guests over to their home for one to two hours, serving drinks and canapés as they introduced their friends to each other. These parties usually took place before lunch or dinner; guests moved to another location to eat. Modern cocktail parties hosted by hotels and bars often host cocktail hours as a way of enticing guests in to stay for longer periods.
