Much of what is known about the costumes of ancient Greek theatre is based on artwork found on pottery and wall frescoes, as the costumes themselves were made of disposable materials and did not survive until the modern age. It is known that they consisted of robes and masks, and that they were decorated with unique and distinctive features.
In classical Greek theatre, only three actors would play all of the speaking parts in a play, so it was important that they had distinctive costumes for each character they were portraying. This made it possible for the audiences to tell who each was playing in each scene. These costumes also told the audience what social status the characters were, as well as whether they were male or female and if they were human or perhaps an animal or a god.
The robes worn by actors were similar to the basic clothing of the period, though they were often more decorated than everyday robes. The chiton was made of linen or silk and worn long down the legs, while the hemateon was a wool cloth worn over both shoulders. When playing female characters, the male actors would also include a prosternada and a progastreda in their outfits. The prosternada imitated breasts and the progastreda imitated a woman's belly.
The masks worn by the actors would each be distinctive as they were used to help the audience differentiate between the characters. Those used for a tragedy would have downturned mouths and "sad" features, while those used for a comedy would have upturned mouths and "happy" features. All masks had specially created lips and mouth openings that helped the actors' voices project over large spaces so that everyone in the audience could hear them.
The chorus included several people who stood off to the side of the stage, or sometimes below or above it, and narrated certain scenes that took place. The members of the chorus would wear matching robes and masks, as is was not necessary to be able to distinguish them from each other as it was with the actors.