The fabrics used to make them, are usually very similar to those employed for the evening dresses, and that means chiffon, velvet, satin and taffeta.

The length of cocktail dresses is changes according to fashion and the local customs. It can in fact stand between just above the knee and the ankle. It is called "tea total length" when it reaches about 5 cm above the ankle, while it is called "evening dress" when it almost touches it.

Before the first half of the 20th century, this particular kind of dress was known as "late afternoon", when gentlemen were used to wear suits and ties, "black tie". 
Ever since 1980 the length was no longer the way by which a certain garment was considered to be a cocktail dress, but instead it was its level of magnificence.
Around the mid-twentieth century, a few tailors described the cocktail dress as "costumes for dancing".
The term "cocktail dress" was first used by Christian Dior, referring to the dress that a lady would wear in the late afternoon.