Wash drawing: a drawing made by a brush in washes with a single pigment of black or dark coloursoluble in water, to be reproduced by the half-tone process.
水墨画：用毛笔沾溶于水的黑色或深暗颜色绘画有浓淡色调的单色画。复制时，需用半色调方法。
2
Analysis of the pigments extracted from the tea dhool indicated that the soluble pigments of the brew of green tea increased and its colour got darker in the manufacturing process.
对绿茶制造中颜色的变化研究表明，在制造工序中，茶汤颜色不断加深， 水溶性色素种类增加。
3
A new water-soluble sulfur black was applied in dyeing of cotton textile. The dyeing methods were studied and colour fastnesses of the dyed cotton were tested.