After dyeing with direct dyes, it is best to boil it, so that the color will be brighter and will not fade. Of course, soaking is ok, but if the color is lighter, the boiled color will enter faster and the fixation will be faster. Over and over again, the floating color disappears and does not fade. Not bad. However, some people dye it with propylene, which will be easier to use and more troublesome to cook.