Burnished

Burnished or burnishing is the process making a pottery surface smoother and polishing it using a hard tool to compact the body surface and edges while pottery still in a dried leather-hard state before it is fired. After firing the piece is rubbed again with a hard tool until the surface is even and has a rich sheen. This was used by potters before the invention of glazes to make pieces more water tight as well as to finish them with a soft, tactile and subtle beauty.