ingrained (adj.)

"deeply rooted," 1590s, literally "dyed with grain "cochineal," the red dyestuff (see engrain). Figuratively, "thoroughly imbued" (of habits, principles, prejudices, etc.) from 1851. In reference to dyed carpets, etc., it is attested from 1766, from the manufacturing phrase in (the) grain "in the raw material before manufacture."