This is crucial. If an artist doesn’t make their own henna paste or purchase paste from a professional henna artist, do not hire them. The reason being is for safety; store bought, commercial cones are made with unknown ingredients and have stabilizers and preservatives to retain their ability to stain and survive their life on a store shelf (although this stain is usually a very poor quality anyway). The best and most safe henna paste is made by the artist because they will know the ingredients used as well as when it was made. Store bought cones with preservatives can harm skin so they should not be used on anyone. Professional henna paste is safe for all skin types that have no sensitivity to the essential oils the artist used. Pure, professional henna is made with henna powder that consists of USDA Organic henna leaves that stay vacuum sealed until mixing. The paste will consist of two essential oils (tea tree, lavender, cajeput, frankincense etc.) , water, a sugar, (maybe lemon juice or tea water) and nothing else . The paste should remain frozen until right before use. Henna should smell earthy, not pungent or sour. When you are speaking with an artist prior to hire, ask what they make their paste with and how they mix it. If they can’t tell you, do not hire.