Denim cotton warp yarns are rope-dyed with a benzoquinone dye of the general formula
 in which each of R₁, R₂, R₃, R₁′, R₂′ and R₃′ is hydrogen, halogen, alkyl, cycloalkyl, alkenyl, aryl, aralkyl, alkoxyl or alkoxyalkyl, alone or together with a red Δ2,3′-biindolin-3,2′-dione dye and/or a blue indigoid dye or sequentially with the latter.
                            用通式如下的苯醌
染料对牛仔布棉纱进行绳状染色
 其中 R₁、R₂、R₃、R₁′、R₂′ 和 R₃′ 各为氢、卤素、烷基、环烷基、烯基、芳基、芳烷基、烷氧基或烷氧基烷基,可单独或与红色 Δ2,3′-联
吲哚啉-3,2′-二酮
染料和/或蓝色靛蓝
染料一起使用,也可先后与后者一起使用。