Shaiban to dirty little experience

In the typographical version, especially the tanning version, microscopic dirt spots are attached to the film due to the electrostatic effect of the film. During the air extraction process, these dirty spots are hardly visible to the naked eye, but with the prolonged extraction time. At the end of the exposure, these dirty spots will appear. At this time, the film should be removed, use absorbent cotton and alcohol to wipe the dirt (note that the layout can not use alcohol), and then the film and the rules of the right, and re-evacuation more than 40s, exposure only 5 ~ 6s can be Remove dirt spots.

Author: Wang Wei a

Reprinted from: Printing Technology