1. Dichroism
The reasons may include poor quality of the original, inaccurate plate making, inconsistent control of printing conditions, good ink control, non-standard light source of the sample stand, etc.
2. The color is dim and not bright
The reasons may include poor quality of the original, poor design of the plate making curve, low density of color separators, poor printing, insufficient printing pressure, aging of the printing machine, excessive fountain solution, rough paper, low whiteness, etc.
3. Writing water
The reasons may be low positive image density, high film haze, poor printing, insufficient printing pressure, aging of the printing machine, excessive fountain solution, insufficient ink, etc.
4. Paste version
Due to the overflow of ink on the image and text of the printing plate, the print on the substrate is not clear, which belongs to offset printing fault.
5. Dirty edition
Due to the poor wetting part of the printing plate, the blank part is inked.
6. Version dropping
The fine tone of the image and text of the lithographic plate becomes lighter, the area of the dot and line decreases, and even loses the ink affinity.
7. Increase of outlets
The dot area of the substrate is larger than that of the corresponding part on the printing plate.
