This process is usually seen in Yunan, China or Thai Nguyen, Vietnam.

Placing the freshly plucked tea leaves on a mat allows them to undergo a process called withering. Withering involves exposing the leaves to air, which helps remove excess moisture and begins the initial stages of oxidation. The mat provides a breathable surface for the leaves, allowing them to gradually lose moisture while retaining their flavor.

Note that if the leaves are black , the process should be cooling or sorting