Ceramic lustres are precious metals in liquid form that can be painted on to fired ceramic surfaces to produce metallic and iridescent effects.
Lustres are micro-thin coatings of metallic substances fired at comparatively low temperatures (e.g. cone 018, 1350F) onto already-fired glaze surfaces. They produce metallic and iridescent effects. The liquids are precious metals dissolved in hydrocarbon solvents with resin hardeners. Common materials used in lustres are metal oxides chlorides of tin, barium, silver and sodium, bismuth subnitrate (even gold, platinum and palladium compounds). Luster colors have strong solvent doors so safety precautions must not be ignored.
Ceramic Colours and Pottery Decoration by Kenneth Shaw, published by Maclaren and Sons Ltd., London, 1962, reissued 1968.
Lustres by Margery Clinton, published by BT Basford Ltd. London, 1991. This book covers how to make and use lustres.
Here is an example of research done by one artist researching various brands of gold luster, evidently they are not created equal. It is apparent you will need to be willing to do testing.
Colorobbia BRIGHT GOLD Contains 10-11% gold by weight.
BRIGHT GOLD (From ITALY – 24% / 20 karat gold – a true gold, Liquid form (DBA China Paint supply)
SATIN GOLD – Roman Burnish Gold in 35% gold (DBA)
Silky Matt Gold from Germany, 25% gold content, 20 karat gold (DBA)
Duncan OG801 Liquid Bright Gold 2 Grams 7% gold
Duncan OG805 Premium liquid bright Gold 2 Gr. 11% gold
A method of applying decoration over the glaze surface of ceramics. It can be done before or after the glaze firing.
Production of Lustres by C.L. King
Johanna Demaine excellent discussion about the hazards of ceramic lustres