Art ceramics cannot be imagined without intense colours. The brightest red, orange and yellow can be achieved with cadmium and selenium glazes. Intense green colours can be obtained by adding 0.5 to 1% by weight of cobalt stain to the yellow. Mix glazes for a short shelf life and be very meticulous in avoiding contamination from metal equipment.
The success of the firing depends strongly on the firing time and the kiln atmosphere. The best is a short firing cycle, good air circulation and good space between pieces in the kiln. Only load the kiln with cadmium/selenium glazes because vapour (say from bisque) and fumes from other glazes (e.g. copper) may adversely affect results.
Toxic material, hazardous as airborne dust, and/or as powder and/or in liquid suspension If applied properly, the glazes release only very limited amounts of lead and cadmium. This release strongly depends on the firing conditions and other parameters, which are difficult to define. If the glazes are used for food containers, the glazed ceramic pieces must be analysed for lead and cadmium release.