aniline definitionAniline is a colorless, toxic and oily substance. It is an intermediate originating from benzene (which originates from coal tar distillation). Frequently aniline is employed to make resins, varnishes, rubber and compounds to make medicinal drugs. Generally, color pigments and man-made dyes were in the past termed aniline colors as a result of the first man-made dyes and several other dyes being created from aniline colors. However, colors created with aniline are often not permanent; this has caused a negative connotation to be associated with it. Nowadays, the term synthetic organic pigment is used to refer to colors made from substances taken from coal tar. The term aniline may also refer to a type of delicate leather that is worked on in order to improve the natural appearance of the hide. The leather is frequently dyed. Since it does not contain a protective coating, staining happens frequently on aniline and the stains are permanent.