墨汁

cóng wù lǐ xué de jiǎo dù lái fēn xī mò zhī yù zhǐ de mó cā kě yǐ dá dào lì tòu zhǐ bèi rù mù sān fēn de xiào guǒ

从物理学的角度来分析，墨汁与纸的摩擦，可以达到力透纸背、入木三分的效果。

From a physical perspective, the friction of ink and paper, could achieve forceful and penetrating effect.