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Stains are used to colour (or stain) glazes, underglazes, slips & engobes. Stains are fritted to assure uniformity of results and are therefore superior to raw oxides; although even as with oxides, each new batch can vary and must be tested. The depth of colour will increase with the amount of stain used and they may be intermixed to produce other colours. For a purer, more even and intense colour, the stains may be ground with a little water & spatula on a glass slab or in a mortar & pestle.
Stains can be added to any glaze to impart colour. The make up of the glaze can effect colour development and the notes on Mason stains as to glaze composition should be investigated prior to using the stain in any particular glaze. To give you an example a lot of stoneware glazes containing zinc will leach out the colour of the stains. Therefore we recommend WSG31 Zinc Free Clear Glaze for Stoneware.
Recommended Base Glazes

To a clear glaze, stain will give a bright vivid colour and to a white glaze it will give pastel shades.
Stains can be added to glazes up to about 10%. When stains are being added to glazes it is best to run the mix through a sieve prior to use, this minimises specking of the glaze. The sieve size should be at least 120 mesh preferably 200 mesh.
Body Stains
Some stains are more satisfactory body stains than others. Varying the percentage of a stain added to a body or a slip will give varied strength of colour. It is most important that when a stain is added, the body should be sieved through the finest sieve practical to minimise specking, 120 mesh is recommended.
In some cases the addition of the stain will alter the glaze to body fit, this should be tested first. In other cases, for example with the cobalt stains, it can effect the fluxing temperature of the body, again this should be sample tested first.
Adding stains to a plastic body- this is slightly more difficult. You can mix the stain with water and paint the stain on to layers of plastic body then joining and hand wedging them together. The more you wedge the better the colour blends through the plastic clay. Prior to painting the stain it would be best to run this mix through a sieve to minimise specking, 120 mesh is recommended.
Preferably with plastic bodies it is best to dry them out, add the stain by weight, mix up with water to a fluid state, run the blend through a sieve, 120 mesh is recommended, then de-water on a plaster batt.
Mixing Suggestions

Stains can be blended into prepared engobes. The stain can either be added as a powder and mixed with the engobe thoroughly and then sieved, or because the engobe is quite viscous it is preferable to mix the stain with a small amount of water, mixing it into a paste form and then mixing into the engobe. This way the specking is kept to a minimum. It can be reduced further by running through an 80 or 120 mesh sieve.
Mixing Suggestions

Stains should be mixed with Walker Brushing Medium to impart some green strength, good flow characteristics and also to act as a suspension agent. It should be mixed to the consistency of smooth cream. The stain can then be applied to either green or biscuit ware and allowed to dry before glazing.
Some recipes used in the field are as follows

Due to different refractory properties of different stains the amount of flux addition may vary.
Care must be taken to keep the stain application thickness to a minimum. If stain is applied too thickly it can peel off during the drying, glazing or firing stages. It is best to practice first on a sheet of paper to get the right decoration and application thickness. Water can also be used as a medium but the application will lack green strength and good flow characteristics. This is the reason the Walker Underglaze Medium is recommended.
If the stain is being applied to greenware and then is to be bisque fired it is advisable to add 5 to 10% of a clear glaze maturing at the same temperature as the ware you will be firing. This will impart some fired strength to the final stain. If a flux is not added, the stain can tend to powder or rub off after biscuit firing, risking smudging or finger marks on the ware. The addition of the glaze prevents this. This does aid adhesion of the stain to the body if applied to bisque ware and also proper merging of the colour and glaze.
A body slip can also be used as an addition to these stains to impart green strength, fired strength and binding to the body.
Stains can also be brushed on over an unfired glaze to impart a softness of colour decoration to your ware. This technique is known as majolica. The stain is mixed with underglaze medium and the colour then brushed onto the glazed but unfired pottery. Stains applied in this way will have a much softer edge than applied underneath the glazes as the stain will melt into the glaze during the glaze firing.
Mason and Walker stains can also be used to alter the colour of the Walker Ceramics Liquid Underglaze range. The stains may be added to white or any other colour in powder form, mixed thoroughly and preferably run through a sieve to minimise specking before applying to your ware.
Mixing Suggestion