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Ink back transfer is a frequent post-printing defect for stacked thin printing paper and coated magazine paper, distinct from ordinary ink rubbing off. After color printing, when printed sheets are stacked tightly under pressure, unconsolidated ink pigments seep backward through paper pores to contaminate the reverse side of the upper paper sheet, forming blurred reverse ghost patterns. This defect occurs mostly in high-speed offset printing with fast stacking speed, and severely damages double-sided printed products, brochures and high-end catalogs. The root cause lies in mismatched paper pore permeability and insufficient ink anchoring capacity of surface fibers; single-sided surface strengthening only improves front ink fixation and cannot block reverse penetration of loose ink particles. Printing factories add large amounts of ink fixatives to solve the problem, which increases printing auxiliary costs and slows down assembly line circulation efficiency.

Shandong Ludao Energy Technology Co., Ltd. provides anti-ink-back-transfer paper optimization schemes. By constructing gradient micro-pore structure on paper surface, we realize moderate ink locking without hindering normal color rendering, block reverse seepage of un-dried ink pigment under stacking pressure. The technology adapts to water-based and offset oil inks, does not extend ink natural drying cycle, completely eliminates reverse ghost pollution of stacked printed sheets, improves double-sided printing finished product yield, and cuts downstream printing auxiliary material consumption.