Lesson 6
LUSTRE TRIALS
A large choice of lustres are avalaible in liquid form. Lustres are a mixture of mineral salts, bismuth, resins and oils. When heated the resins and oils burn out freeing carbon that combines with the mineral salts to form, on the decorated surface, a very thin layer of metal that the bismuth help to adhere to the enamel.
Contrary to on-glaze enamel powder paints, lustres do not contain enamel but get their shine from the object on which they are applied. Faïence, ceramic, porcelaine and even glass can be decorated with lustres. ( However, when decorating glass do not exceed a temperature of 600°C as the glass would melt). Lustres scratch easily not just because they do not contain enamel but also because they do not merge with the enamel of the piece they decorate . They, therefore, must not be used for food purposes.
Contrary to on-glaze enamel powder paints, several layers of lustres can be applied with in between firings without risk of cracks.
When firing lustres, the kiln must be situated in a separate room, well ventilated. The vapors and combustion gas are toxic.
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| lustre alone | lustre with marbling solution |
| Before firing | |
TESTS:
For the trials the following lustres were used:
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Amber ( Ceradel - LC 231 ),
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Blue green ( Ceradel - LC 250 ),
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Mother of perle (Ceradel - LC 282),
Along with:
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thiner (for lustres) ( Schjerning - 174 )
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marbling solution
Lustres can be applied either with a brush or sponged. The results, of course, are different. All the material used ( porcelain pieces, brushes, sponges,...) must be perfectly clean.
- The picture on the other side shows the sponged lustre first without and then with marbling solution applied with a brush in a single layer.
First trial: Amber, Blue-green & mother of perle lustres were sponged individually direct from the phials. Fire at 800°C.
Second trial: Blue-green & Amber lustres were diluted with Schjerning thinner N° 174.
Preparation: add 20% thinner (2 drops of thinner for 10 drops of lustre), mix in a little dish and sponge. Fire at 800°C
Third trial: Amber lustre with marbling solution & Blue-green lustre with marbeling solution.
Preparation: Sponge the lustres. After they are touch dry (15 to 20 mns) spread the marbling solution with a brush. If the lustres are not dry the brush will damage the layer.
Fire at 800°C.
The results were better on amber lustre than on the blue-green lustre.
Fourth trial: Amber lustre & mother of perle lustre with marbling solution.
Preparation: Sponge the mother of perle lustre. After it is touch dry (15 to 20 mns), apply the marbling solution with a brush. After it is touch dry in its turn sponge some amber lustre very delicately .
Fire at 800°C.
Fifth trial: Amber lustre & arabic gum (used as a medium for gouache paints).
Preparation: Sponge the lustre. After it is touch dry (15 to 20 mns), apply the arabic gum with a brush very delicately without damaging the initial layer.
Fire at 800°C.
Sixth trial: Blue-green lustre & arabic gum.
Preparation: Sponge the lustre. After it is touch dry (15 to 20 mns), apply the arabic gum with a brush very delicately without damaging the initial layer.
Fire at 800°C.
Material used: We are selling the products used in this lesson in our on-line shop