Low concentration tended towards greater transparency more brilliant color and higher luster. Silver nitrate in concentration from 0.5 to 2% produced yellow-to-gray colors.
This characteristic in fact was the most predominant feature of metallic luster. Depth and richness seems to be influenced by the extent of reduction and subsequent reoxidation.
Luster effect may be developed at a wide range of temperature after the glaze has been matured but these effects can be retained on cooling only if re-oxidation of the glaze is prevented.
Decorative Techniques: Starting transformation of color and reflectance occurred when luster glazes were applied in moderately thin coats over colored bodies engobes and under glazes and fired.