“See My Scales Where My Feathers Used to Be” 2009, Southern Ice porcelain, clear glaze, lustre, gold, sand etched, enamel, h. 10.5cm, d. 8.5cm
Working with Resinate Lustres.
In his seminal volume Ceramic Colours and Pottery Decoration Kenneth Shaw postulates that lustres are extremely thin films of metals deposited on the surface of ware in the same way as Noble metals and that the lustre effect is due to the interference of incident and reflected light. He further states that lustres are made up of solutions and suspensions of metallic resinates in solutions of polymers and thickening agents to aid application by brush and machine. The colours are due to metallic oxide films bonded onto the glazed surface by bismuth oxide which must be fired to a low temperature otherwise the flux would burn out.
This is the world of lustre that I work within. This is the same lustre film as produced by Reduced Lustre or Arabian Lustre. The main difference is the method of application and firing technique employed. Whereas reduced lustres are either clay paste or water based and fired in a reducing atmosphere, resinate lustres are oil/resin based and fired in an oxidizing atmosphere. The localized reduction is performed by the carbon produced from the resin (usually pine oil) base. Resinate lustres are a product of the ceramic industry as application and controlled firings were standardized for mass production. Resinate lustres are also known as Oxidation or Commercial Lustres. This thin film of metal then dictates the way in which I work..
Lustre takes on the surface qualities of the ware that it is applied to. Surfaces with gloss glazes will be shiny, matt glazes will be satiny matt, vitrified bisque will be very matt. As the lustre bonds at the softening temperatures of the substrata, there is a wide firing range to encompass glass, earthenware, bone china, stoneware, hard and soft porcelain (this refers to the glaze types used). Using a medium to hard glaze on my porcelain I fire to 810.c. Some hard glazed porcelains successfully fire at 850.c
Lustre is oil based so that it will adhere to a glossy surface. However the surface has to be scrupulously clean. Any grease, sweat and oils from the skin, lint and dust will repel the adhesion of the lustre. There are 2 methods I use for cleaning the surface of the ware. I mainly use methylated spirits but there are certain brands which will actually leave a film on the glaze and repel the lustre. If this happens I either put the ware through the dishwasher (I use white vinegar as my rinse aid) or use detergent and very hot water until the water sheets off the pot. It is then dried with a lint free cloth and I have no further skin contact with the pot. I use cotton gloves or towel and put the pot onto my decorating easel (see The Journal of Australian Ceramics , 48/2, page 55).
When applied, all lustres appear a treacly brown with their colour being achieved in the firing process. So I can visualize what I am doing while working, I have made permanent colour charts for each glaze that I use. This is simply a test tile with lustre brushstrokes (labelled), fired and then repeated on the tile turned 90 degrees and fired again. This provides me with a readout of one and two layers of lustre plus many variations of colours when lustre is applied over lustre.
Lustres can be applied by brush, sponge and stamping. Some people advocate airbrushing however this is something I would never contemplate as lustres are based on organic solvents. I use German squirrel hair flat shaders, mainly size10 (the old 3/8′ size). As my technique employs broad areas of lustre, I lay down the lustre in long quick strokes taking care not to overlap drying areas as otherwise these would be more intense in colour. If I wanted a very even surface I would lightly pad or pounce the brushed on lustre with a small sponge or cotton ball wrapped in a square of silk held tight with a rubber band. This will even out the brush strokes but will also lighten the lustre considerably as you are pulling off excess lustre. If I get lustre on my skin I immediately remove it with meths as I am conscious of the fact that the skin is the largest organ of the body and absorbs toxins very efficiently. I use multiple layers of lustre, firing between each layer.
Keep lustre brushes only for lustre as other mediums will contaminate the brushes. To clean them, part fill two small glass jars with lustre essence, (I prefer citrus solvent) and one jar with methylated spirits. Swish brush in first bottle, blot on tissue, then swish in the second bottle of lustre essence and blot again, then swish in the meths bottle and blot. Finally work Morning Fresh detergent into bristles and rinse exceedingly well under warm running water. Blot on tissue and dry flat.
At present I am exploring two processes – resist and etching. This focus will be on the resist technique which I use so as to limit my exposure to lustre; 90% of my time with lustre is spent in applying inert resist and only 10% in actually applying the lustre.
Most resists, apart from waxes, will work as lustre resist. Latex, white poster paint, adhesive tapes, masking laquers, stickers, white-out pens, and proprietary lustre resists can all be used. I prefer to use Fay Good’s black lustre resist as this resist can survive several firings without having to be cleaned off and reapplied – essential for the way I work. The attached storyboard illustrates my method.
2. Outline drawn in water-based OHP pen.
3. Drawn with black resist using tjanting.
4. Lustre applied as follows: mountains purple, fields yellow, water light blue.
5. Fired plate, resist removed.
6. resist reapplied everywhere except the water area; another layer of lustre applied.
7. Second firing, resist left on.
8. Resist patterning applied to mountains and fields; mountains coated with gold, fields with cinnamon; gold penwork over water.
9. Third firing; resist removed with Jiff.
10. Detail of patterned layers.
11. Tools used: 2/8 inch and 1/2 inch squirrel flat shaders; tjanting for resist; gold pen for penwork.
I sketch my drawing onto the glazed surface with a non permanent black OHP pen. I then go over this adding detail with a Tjanting filled with the black lustre resist that I have adjusted to flow through the tip. When the resist is dry I apply an even layer of lustre in the areas required just the same as for any other painting technique. I then fire to 810.c in approximately 5 hours. I don’t subscribe to the fast firing of china painters as I believe that all processes such as glaze softening takes time not just temperature. Also I never lose any pots due to cracking.
After the first firing I continue adding layers of lustre to deepen the colour, firing between each layer. As well I add further resist to help the layering effect that I am after. After the final lustre layering, I will either add penwork with a gold pen, or use raised enamel for accent. I remove the resist by gently cleaning the surface with Jiff. Do notuse Ajax or any other abrasive cleaner as it will scratch the surface.
Health and Safety
When working with lustres I take the issue of H&S very seriously. Please read this article in conjunction Health and Safety and Overglaze The Journal of Australian Ceramics, 45/3, page 91-94. This article is also available on my website http://overglaze.demaine.org
Lustre for China Painters and Potters: Heather Taylor, 1990, Kangaroo Press
China Paint and Overglaze: Paul Lewing, 2007, The American Ceramic Society.
Ceramic Colours and Pottery Decoration: Kenneth Shaw, 1969, Frederick A Praeger,Inc
Resist and Masking Techniques: Peter Beard, 1996, A&C Black/Craftsman House
Health and Safety and Overglaze: Johanna DeMaine, 2006, The Journal of Australian Ceramics, pp91-94, Vol 45/3