50cm×70cm, 57cm×84cm. According to the relevant information, the sizes of Kugou promotional posters and commercial posters are 50cm×70cm and 57cm×84cm. The name "poster" originated in Shanghai as a way of publicity. Posters are used for performances and events such as dramas and movies. People in Shanghai usually call professional theater performances "hai", and Professional theater performances are called "going to the sea", and people call them "posters" because they are promotional posters that attract customers as information about the play's performances.