The investment of labor required to transform clay dug from the ground into a workable "plastic" medium is significant.
We see this by observing local Palestinian potters who keep the "ancient craft" alive.
In this image, Amzi (the son of Abu Ali who is pictured here) prepares one of several settlement basins beside the family shop in Aqabat Jebar (a refugee camp south of Jericho). He lines the basin with a layer of fine-grained sand. The particles will keep the clay from sticking to the bottom of the basin when it is mixed with water and allowed to settle.