Silver stain works differently from paint. Paints are powders that are fired to melt on the surface of the glass and adhere to it. The actual potent ingredient in silver stain is actually not colored or visible, so it is kept in a colored matrix of clay material so you know what you are working with. During the firing, the stain leaves the matrix, enters the glass, and actually stains it. Once fired the clay matrix needs to be rinsed off the glass to uncover the stained area.
Another particularity of silver stain is that it is usually painted on the underside of the glass, and when fired, it is fired with the silver stain against the kiln shelf, rather than facing up. There are a few reasons for this. One is that silver stain is done after the tracing black and matte, and if paint the silver stain on top of the tracing black and matte, the colored clay residue melts into the tracing black and matte and leaves an unattractive dull finish and a colored cast. Another is that placing the tracing black and matte side of the glass against the kiln shelf will cause the paint to fuse with the kiln wash, leaving ugly marks on your art work. Furthermore, this fusion with the kiln wash will cause uneven contraction/expansion of the glass during firing greatly increasing the risk of cracking.
If you have used a kiln shelf with silver stain face down, you MUST remove the kiln wash, and apply a new layer after the firing. This is because, as said earlier, the silver stain itself is invisible. There may be a lot of it seeped into the kiln wash. You would not see it. But next time you fire something on that shelf, the glass WILL PICK UP the invisible stain, and stain your piece with unwanted yellow.
REMINDERS for SILVER STAIN:
Below is a photograph of the finished matting, backlit:
Below is a photograph of the finished matting, with front lighting:
This stain is "amber stain H465." It has been giving good intense results under my conditions, while the orange stains have yielded nothing but a wan yellow.
Silver stain fires lower than tracing black or matte, the same temperature range as enamels, 1050-1080F. However, silver stain can actually fire as high as 1250F without adverse effects, so it is sometimes a matter of convenience to fire your silver stain along with a batch containing tracing black and/or matte.
Silver stain is very tempermental, and results will vary with the type of glass you are using. Artists working on large projects will perform tests, but those working on small pieces may just take their chances. Although some silver stain is advertised as vivid orange, be prepared to be disappointed with the results being the usual yellow, quickly darkening to ochre (almost in a stepwise, binary fashion) if applied especially thick. This darkening is difficult to control and rather unpredictable.
One trick to make the silver stained areas more lively is to apply the stain twice, with two firings. This way, you have considerably more control over the various shades within your yellow/amber range, can achieve deeper colors without stepping up to ochre. As yellow covers a very narrow range of wavelenght, making the effort of including many intensities within it is very rewarding to the eye.
After the clay material has been rinsed off the glass surface, this is the appearance of the silver stain: