Strike-through: The penetration of ink or ink vehicle from top side of paper to the underside causing stain to appear. The causes would be too low viscosity of the ink and too absorbent of the paper.

• 透背:油墨或展色剂从纸面透过纸张，在纸背现出污痕的情况。原因是油墨的流阻度过低，纸张的吸收性极强所引致。