Non-image area of the paper changes slightly yellow as if oil penetrates.

INK

● Paper adsorbs the gas which is from the decomposition of the drying oil in its oxidative polymerization process, and turns yellow.

● Replace with ink which contains less drying oil.

PAPER

● Heavier coated paper adsorbs more amount of gas. (uncoated paper hardly adsorbs gas.)

PRESS

● The larger amount of ink is applied, the more gas is generated.

● The longer the papers are stacked at press room, the more gas the paper adsorbs.

● The higher temperature during paper stacking is, the more actively gas is generated.

● Avoid using too much ink.

● Use starch powder as much as the effect of prints are not disturbed, and apply enough wind to the paper.

● Let gas go out by wind while drying.

● Avoid long stacking time.

● Do not keep the prints in high temperature and high humidity