Assertion: vase's opening | /r/CapableOf | make centred hollow
Facets:
value: into the solid ball of clay
type: OTHER
Source sentences:
text: The first step of pressing the rough ball of clay downward and inward into perfect rotational symmetry is called centring the clay—a most important skill to master before the next steps: opening (making a centred hollow into the solid ball of clay), flooring (making the flat or rounded bottom inside the pot), throwing or pulling (drawing up and shaping the walls to an even thickness), and trimming or turning (removing excess clay to refine the shape or to create a foot).