Do you need a printing machine for negative or positive films? There are negative films of D printer, positive films of D printer and negative films of D printer. Do you need a printing factory? Just get used to it. You'd better ask first If the printing factory is used to using all positive and negative plates, then use them, while there are D positive and negative plates at home.

I read that the negative film has to wait for the film to hang down, and the film on the negative film will turn white, and the film on the negative film will turn down like that on the positive film. However, Cuter can be used to remove black powder when the film is low. This kind of film is mostly used for screen printing and pad printing, and the hanging film is better than the film on the negative film. The film on the positive film, that is, the film on the front, can be used to remove the black powder of general four-color printing. My experience is, hmm!

Actually, there is nothing to say. What time? The most important thing is to use the zinc plate after buying it. If you use zinc plate, of course, zinc plate will be positive, on the contrary, zinc plate will be negative.

Reference: self