Halmaddi is a form of resin which is often incorporated into incense. It is harvested from the Ailanthus Malabarica tree. It is thought to smell similar to plumeria flowers. In essence, it is quite similar to frankincense and myrrh, the holy resins from the Bible.
These resins are bled from trees and then dried until it takes a brittle shape. Although this resin is most often used as a binding agent, many people swear that it is an important ingredient in nag champa and similar incense styles. Due to it’s hygroscopic nature, which means that the material attracts moisture from the air, incense sticks which have a high percentage of halmaddi usually have a sort of wet feel to the touch.
It is important to note that an ingredient such as this is not usually incorporated into dipped incense sticks and is usually added into the paste when the stick itself is formed.
Supply for this material has dwindled and it is in danger of becoming extinct in the future due to the extreme demand for halmaddi resin. Most of this resin is harvested in India, and used to be a protected species, at some point, India decided not to pursue this further.
I personally like the scent of halmaddi and wish they added as much of it as they used to, but that doesn’t seem to usually be the case anymore.