It deforms when it bulges. It may be deformed by heat or other reasons. If the requirements are not high, you can wipe the surface with an alcohol dip cloth. . You go to print at this time It will be much clearer. After wiping, drip oil where there are words. A little is enough. Put it upside down after dripping. Wait for the oil to penetrate. After ten minutes, it's ok to wipe off the surface without absorption with a dry cloth.

But it must be matching oil. Otherwise, this chapter will be abandoned.