They are not soluble in water and hence they cannot be applied directly on textile like direct dyes. They have to temporarily convert into a water soluble form, which must have higher affinity to cotton than its water solubility and then applied to cotton at an appropriate temperature and then heating the solution while stirring the yarn so that it picks up the dye uniformly to give even dyeing effect. Finally the water soluble form should be reconverted into the original insoluble form after being taken up by the cotton. This dye has good washing fastness. They will not bleed out in the hot soap solution used in washing of the dyed clothes.