Enamels on copper plate on silver

Various pieces of PMC had areas that were electrolytically copper plated, then covered with areas of reptile green and ruby red transparent enamels. On firing the results were mediocre, however with hindsight I realise that I chose two unpromising colours - in particular reptile green goes brown on copper, rather than the beautiful green it goes on silver flux on copper. I then went on to embedding small copper shapes in PMC and applying enamel, though in most cases coping with the oxide was the biggest problem.

Detection of mercury vapour

After some research in my chemistry books, I settled on cuprous iodide / silver iodide paste mixed with precipitated sulphur as a possible reagent. The reagent was made by double decomposition of silver nitrate and copper sulphate solutions added to a solution of potassium iodide. The resulting yellow paste was painted onto filter paper and allowed to dry. On exposing to mercury vapour in a glass vial, the exposed area turned a satisfying but not very visible light amber colour. I doubt that it would detect the vapour from the mercury spill which occurred some years ago in the kiln room...