Although silver can be an excellent inclusion in glass, and foils
and leaf can work very well when sandwiched between two layers of
glass, be aware that silver can also cause problems in the kiln.
This is especially true when using silver in wire, powder, or
precious metal clay (PMC) form.
If residue from silver is left on the kiln shelf or anywhere
inside the kiln and it comes into contact with glass during a
subsequent firing, this can leave ugly brown spots on the glass.
The contamination from the silver can permanently stain the glass.
Firing on fiber paper or re-washing the kiln
shelf may not be sufficient to prevent the silver from contaminating
the kiln. In most cases the contamination is not visible on
Instead, you should consider dedicating a specific
kiln shelf to firing with silver or PMC firing also. Keeping
the silver confined to a different shelf than the one you use for
"normal" firings will help keep the contamination from ruining your
Copyright 2005 Brad Walker.
All rights reserved.
This tip was adapted from
comments made by
posters on the Warm Glass bulletin board.