ULTROX (Zirconium Silicate Flour)

Description

Zirconium Silicate powder called by its trade names Ultrox or Zircopax is the main opacifier in ceramic glazes.  8-10% in a glaze will yield an opaque white color.  It also benefits ceramic glazes by reducing thermal expansion (reduces crackling or crazing of glazes) and hardens the glaze surface.  It also act to stiffen the melt of ceramic glazes.  It is the most cost effective material to opacify a glaze.  Tin Oxide is also an effective opacifier but the high cost limits it’s practicality in large scale usage.