Yin film: The picture and text part is white, which is the myrrh model.

Positive film: It is the kind you use, the picture and text part is black.

A negative film is a negative film, which means that the color and direction are reversed (the black characters on the film are white, and the direction is reversed), and the positive film is a positive film, and the color and direction are normal

Silk screen printing is a positive piece, with the film facing up

Offset printing is a positive piece, with the film facing down

Letter printing is a negative piece, with the film facing up