My henna paste contains sugar. This keeps helps keep the the paste from crumbling off once dried. The sugar literally sticks it to the skin. I also seal it with a sugar and lemon paste twice to keep it moist and help the sticking process further. The lemon of course helps deepen the colour.
After sleeping on this overnight, the paste is crumbled off at the sink (without any water) to reveal a bright orange stain. This oxidizes and by the time I make my morning tea, it's already deepening. 36 hours and a sleep later, my stain is a rich mahony. After another sleep, the stain is a rich deep dark brown stain with bolder parts turning almost black and the lighter parts providing a stunning contrast. Henna is made fresh using normal kitchen ingredients and essential oils. No harmful chemicals are used.