Printing ink added too much dry oil or semi-finished products stacked for too long, easily lead to drying too fast, the surface of the blot appears vitrified, the surface of the blot is very smooth, loses adsorption capacity, the latter color ink printing can not go up. This phenomenon is common in full-field printing, especially yellow ink or line prints. In this case, the following method can be taken. 1. It should be prevention. For the viscous yellow ink, appropriate amounts of excipients such as Weili oil and magnesium carbonate powder are preliminarily added to make the surface of the film rough or extend the drying time, which has a certain effect on the prevention of vitrification. 2. If vitrification is already present, the latter color cannot be printed. If the number of products is small, a soft cloth can be used to dip the magnesium carbonate powder and lightly rub on the surface of the printed sheet; if the quantity is large, caustic soda water can be overprinted once, or the original yellow version can be used. Oil mixture. When applying Invitrogen oil, it is necessary to add a mixture such as dibutyl phosphite to be effective.
Source: Printing Technology