Common problems in printing.
Off-color: The reasons may be poor quality of the original, inaccurate plate making, inconsistent control of the drying conditions, poor control of ink color, the non-standard light source of the viewing table, etc.
Dull color, not vivid: the reasons may be poor quality of the original, poor design of the plate curve, low density of the color separation film, the unrealistic printing plate is too light, insufficient printing pressure, printing press aging, excessive fountain solution, paper roughness, low whiteness, etc.
Watery text: The reasons may include the low density of the Yang chart, large film gray haze, unrealistic printing, insufficient printing pressure, aging of the printing press, excessive fountain solution, an insufficient amount of ink, etc.
Glued plate: due to the plate graphics part of the overflow of ink, resulting in unclear prints on the substrate, is a failure of offset prints.
Dirty plate: because the plate wetting part of the bad, resulting in the blank part of the ink.
Off-plate: flat printing plate graphic fine tones become shallow, dot and line area reduction, and even the loss of ink-friendly.
Dot increase: the dotted area on the substrate than the corresponding part of the printing plate dot area increase.
Pile of ink: ink or other substances deposited on the ink roller or blanket, forming relief-like deposits, affecting the ink and print transfer.
Deinking: metal ink rollers by the erosion of the wetting solution occur oxidation and rejection of the ink phenomenon.
Printing failure: One of the phenomena that affect normal production or cause defects in the quality of the print in the printing process.
Ink emulsification: the phenomenon of ink absorption of wetting solution in the printing process or due to excessive absorption of wetting solution in the ink caused by printing failure.