There is two diffrent type of sudanese HEnna,

there is natural henna,where the lady needs to spend some time in preparing and laying and waiting until it dries and remove,then allow an extra day for the henna to fulfill its coulour in black,this needs a sudanese woman to offer you the skills to meet the target of all black Henna.

Alternatively, you may use the saloon one,which can be done in few hours and it will last for a few days,however,it contains some chemicals and you have to handle with care.

thankx