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All our glazes,  are available in liquid (Brush on) and powder form (except Raku and Middle Fire which are only available in powder).  We have divided our glaze section as follows: 

* Earthenware Lead Free

* Earthenware containing Fritted Lead

* Middle Fire 

* Stoneware

* Raku 
and each section gives specific information relating to that particular range. 
General information:
Some types of glazes may release lead and other metallic compounds when attacked by certain acids - notably fruit juices, vinegar and alcohol. To reduce the solubility to acceptable limits, we use frits which have a very low lead solubility to meet health requirements. However a 'safe glaze' can be made unsafe by adding even minor additions of certain materials, notably copper. Some of our decorative glazes would fail a metal release test and should not be used on the inside of utility ware. Cadmium Selenium glazes fall into this category and are discussed in the Earthenware Fritted Lead section. Note that the "safe" glazes must be applied and fired under conventional conditions for them to be safe. The decision to use lead or lead-free glazes must, nevertheless, rest finally with the potter in any instance where the ware is intended for use with foods or beverages, especially so if oven-to-table or cooking ware, e.g. casseroles, are to be made. If any doubts are felt about the glaze formulation, firing or the possibility of contamination or additions of such materials as copper compounds, etc., then, certainly the wiser choice would be to use only lead-free glazes, at least on the inside or areas in contact with food.
POWDERED GLAZE
MIXING A DIPPING GLAZE
Sprinkle the powder into a suitable container of water and stir. Leave to settle overnight and pour off surplus water. Stir, sieve through an 80 mesh or finer sieve, then add water if necessary to achieve the desired consistency. This depends upon the porosity of the bisque ware but will be around 500-700gms of powder to 570mls of water.
When some liquid glazes settle out, particularly over a long period of time, they sometimes set hard at the bottom of the container , making them difficult to re-mix. Other glazes may preferentially settle during use and consequently demand thorough stirring or agitation during the dipping session. To correct this defect, a flocculent or "anti-set" solution should be added a little at the time, stirring it in very well until the settling stops.  Add carefully or the glaze will dry slowly on the ware and may cause "mud cracking" and perhaps crawling during firing. The opposite effect of settling is when the glaze appears like thin custard and has a "creamy" feel. The glaze dries slowly on the ware or peels off during drying. Some glazes  which have a high clay content, or raw zinc oxide, magnesium carbonate, talc, etc., or excess dosing of "anti-set" will have this defect. The cure is to add very cautiously, small quantities of a 10% solution of Soda Ash or Sodium Silicate stirring well, until normal drying and behavior occurs.
APPLICATION OF  DIPPING GLAZE
Use either a bucket or Glaze Wok. The type of glaze and the effect desired will indicate how the ware should be dipped: transparent glazes should be thinner than opaque ones; so dip once only. A rutile glaze may be dipped once or twice for varying colour effects.
Walker Ceramics' glazes are delivered with a litre weight of 1500-1750 grams/litre (Specific Gravity (SG) of 1.5-1.75), depending on glaze composition.
Adjusting the glaze to a slip suitable for individual preferences requires the following :
Essential: Dispex, Epsom Salts, Volume measuring device, scale with 1gm tolerance.
Optional : Ford Cup #4, Stop watch
Procedure
Adjust the litre weight to between 1400-1500gms/litre (SG of 1.4 to1.5), by adding clean tap water to the slip.
The glaze slip should have the viscosity of Evaporated Milk or slightly higher.
If glaze slip is too thick, add Dispex drop by drop until viscosity is satisfactory.
Never add water once you have SG correctly adjusted!!
If glaze slip is too thin, add Epsom Salt solution drop by drop until viscosity is correct. (To make Epsom Salts solution, mix 300gms of Epsom Salts with 1 litre of hot water.)
It is highly recommended to use a Ford Cup or Viscosity Cup and aim for run out time of 15 to 20 seconds.
After application the glaze layer should be as thick as the  diameter of a standard steel paper clip.
FOR BRUSHING
Our Brushing Medium has been developed so that it may be mixed with powdered glazes, stains etc. by simple stirring with cake beater or paint stirrer, and running liquid through an 80 mesh sieve.
Suggested proportions are:
For lead-free glazes, approximately 1 litre of medium to 1 kilo of powder.
For lead bearing glazes, approximately 500-600mls of medium to 1 kilo of powder.
Brushing Medium will not deteriorate with time and is non-toxic.
LIQUID GLAZE ( BRUSHING GLAZE)
Liquid glaze is prepared ready to use. However, as materials in some glazes tend to settle on standing, it is important to shake the jar vigorously, then stir, before use. If, after shaking and stirring the glaze it is still too thick to load a glaze brush easily then it may be necessary to add a little water.
PRIOR TO GLAZING
Bisque fire ware to recommended temperature (minimum 1000 C). Sponge bisque with a damp sponge to remove any dust which may have collected. On narrow necked pieces where a sponge cannot work, use a clean damp brush. Do not eat, drink or smoke, as any grease transferred to the bisque will resist  glaze. Although it may appear to cover grease spots when applied, glaze may crawl away when fired.
APPLICATION OF BRUSHING GLAZE
Once the jar of Liquid Glaze has been shaken and stirred, load your glaze brush by immersing the hair right up to the ferrule. Tip glaze of one side of the brush and apply the fully loaded side to the bisque. As an approximate guide, a fully loaded brush will go about 80mm before it should be re-loaded. Apply one even coat, let the "wet" look disappear, then apply the second coat in the opposite direction. When the second coat has lost its "wet" look , apply the third coat in the same direction as the first.
GLAZING THE INSIDE OF NARROW NECKED PIECES
This process should be done before application of the exterior colour. If using Brush-On glazes exclusively, it will be necessary to thin some down for rolling the inside of any ware that cannot be reached by a brush. Do not thin down a whole jar unless it is to be used only for rolling. The addition of water will vary according to the original consistency, however as a rough guide, use three parts liquid to one part water. Replace lid and shake thoroughly. Pour thinned glaze into ware and roll piece around so the glaze can cover all internal surfaces. Pour out slowly whilst still rolling so the glaze can cover the internal lip of the ware. Leave upside down for 5 minutes to drain.
CHOOSING THE RIGHT BRUSH
A suitable brush must be used or the results can be very different from those desired. We recommend square or oval brushes such as hake, camel or ox hair as these will accept a good load of colour. We recommend a brush 20-25mm in size for average sized pieces.