Mehendi : Tips for preparation
Before you make a paste, you will need some good quality henna which you can find in an Indian or Middle Eastern store. There is no guarantee, however, that their henna has not been sitting on a shelf for a long time, slowly losing its power. Wherever you get your henna from, it should have a nice, bright green colour, and should have a nice, grassy, earthy aroma to it. If the colour of the henna is grayish or brownish, chances are it has been exposed to the air for too long or been exposed to sunlight. Your henna should always be stored in a cool, dry, preferably airtight container that does not let any light get in. This will keep it fresh until you need to use it again.
You can find coloured henna paste in the market, but this henna has a lot of colourings added to it, and although it may actually have henna in the mixture, the henna's own colouring properties are overtaken by the coloured dyes that are in it. Do not think of using black henna, for it can actually leave a chemical burn and a scar behind.