Fogging of unprocessed plate : solution
use a new plate, handle a unprocessed an plate unde anr yellow safety lamp.
Poor vacuum contact : solution
check the vacuum frame (drawdown condition of rubber gaskets)
Extend time of vacuum contact
Insert clear film strips between a film positive and a plate to provide air channel.
Too long Exposure time
check the correct gray scale value
Insufficient density of the film positive
Reduce the exposure time, make sure that the GS value is as usual.
Insufficient development
Develop the plate again by processor or by hand. when using a processor check the following points carefully.