"Mandala” originated from Indian Buddhism and is used as a map where the Buddhist deities and relatives gather.
The process of construction of a sand mandala is a detailed and precise one. Each step was made in accordance with the tantra taught by the Buddha, and it remains unchanged. Before using sand, the lamas put on masks and use special cone-shaped containers pre-filled with fine sand to control the flow through light or heavy tapping, leaking the sand on the template, and carefully stacking and delineating. The whole process must be fully focused and meticulous, and the slightest carelessness will wipe out all previous efforts.
more info：Buddhist sand art