Ammonia is a weak base that can be used as an swelling agent on wool fibres before dyeing. In this study the pretreatment of wool with ammonia in different percent solutions (5, 10, 15, 20) is carried out, and its effect on dye-ability of wool by natural dyes such as madder, walnut shell, pomegranate peel, vine leaf, white and red onion skin, is analyzed. Also the effects of temperature, length...