A closer look
One Thai Anthropology Centre record describes clay shaped in a mould and heated. Moulds repeat outlines, while pressing and drying can leave differences. That example does not establish a universal process for all clay or powdered objects.
How to continue
Continue looking: write down visible details and keep interpretations in a separate column. Record viewing conditions, the photograph date and missing information. Revise when evidence changes, so the next reader can see what supported each judgement.
Scope: this is an editorial close reading. References support only the named collection examples or care principles, not authentication of shop stock or claims of religious efficacy.