Zhang Yanzi's ongoing show on herbs, happiness and healing

Two years ago, Chinese painter Zhang Yanzi traveled to the Amazon rainforest in Brazil, and found the local brew ayahuasca, which is made from plants and is said to have hallucinogenic properties. The drink is used in spiritual medicine there.

After she returned to China from that trip, Zhang devoted her time to reading books on traditional Chinese medicine to research herbs used to relieve pain - a subject of interest to her for many years.

Then, she says it struck her that some medicines ease pain by "generating illusion".