Overprint adverse
The phenomenon of wet on wet overprint the back of the printing ink can not be successfully attached to the earlier printing ink.
Compared to the reasons (1) and first printed ink India ink viscosity is too high.
                                             (2) first printed ink fixation is slow and the ink volume.
                                             (3) four-color ink color intensity balance is inappropriate.
Approach :(1) the high viscosity of the ink before printing, low-viscosity ink after printing, the viscosity requirements should be successively lower order of overprint colors.
                   (2) using solid ink printed fast and high concentrations of printed thin, first printed pattern area, in order to facilitate the back of overprint.
                   (3) Any set of wet multicolor overprint ink color intensity is uneven, overprint can be used when the same amount to the ink, if not the same set of ink along the printing, the use is necessary to properly handle.