|Monthly Tech-Tip |
Opax is a brand-name product, it is actually zirconia (zirconium dioxide), Zircopax is a brand-name of zircon (zirconium silicate). Both are used as opacifiers. Zircon is the natural source material from which zirconia is made. Opax does not opacify any better than zircopax, but it is more expensive. And it mattes glazes much more.
Opacifiers are powders that turn transparent glazes opaque by various chemical and physical mechanisms (and combinations of mechanisms).