I purchased an offering set for around 100 Thai baht, or about $3, and joined the line. When it came time to speak with the abbot, I described my intentions: I was not here for a tattoo, I said, but was hoping to take pictures of the monks and their practice. While photography, under normal circumstances, is strictly forbidden, the abbot smiled and granted me permission.
Translated literally, sak yant means “to tap yantras,” a word that refers to the geometric designs used as aids in tantric meditation. Yantras are believed to bring health, wealth, protection and a number of other benefits. The practice is embraced by some Thai monks, though it is not specifically related to traditional Buddhist teachings. The practice’s origins — and its purported effects — are both spiritual and superstitious.
The designs used in sak yant include geometric motifs, animal shapes and divine representations, accompanied by phrases and spells in Pali, an ancient language closely related to Sanskrit.
Article source: https://www.nytimes.com/2021/10/25/travel/sak-yant-tattoo-thailand.html