Translucent glazes are neither opaque or transparent. A good example is a matte glaze that contains no opacifier. Glazes that are opacified will of course have varying degrees of translucency according to the amount of opacifier present. A colored glaze can be transparent, translucent or opaque and the color quality with vary accordingly.
Porcelains can be translucent, for example bone china. The translucency is a product of the degree of melting (the more melted the more translucent it will be) and, or course, the wall thickness. Low TiO2 clays are used to make translucent porcelains.
Every glossy ceramic glaze is actually a base transparent with added opacifiers and colorants. So understand how to make a good transparent, then build other glazes on it.
A ceramic whose priorities are translucency, whiteness, fired strength and resistance to thermal shock failure.
Opacity of ceramics glazes is normally achieved by adding an opacifier like tin oxide or zircon. However there are chemical profiles that can turn transparent glazes milky and make it cheaper to opacify them.