Application of paraffin wax:
The wax, which was initially solid, melted during heating and liquefied.              هنر سفال و سفال‌سازی در قرن پنجم هجری
A sponge is shaped so that it has a sharp point to dip into the liquid wax
And was freely used to apply wax on unglazed pottery.
The wax must be dried before the glaze can be applied to the pottery.