Choosing the right glaze for your pottery project

Selecting a pottery glaze can feel overwhelming when you walk into a ceramic supply shop and find rows of jars with names like shino, celadon, tenmoku, and ash. Every potter eventually develops a personal library of favourites, but the journey there usually starts with understanding the families, the firing ranges, and how a glossy or matte surface behaves on your specific clay body. Whether you are hand-building a small espresso cup at a community studio in Fitzroy or throwing a tall vase in a backyard shed in the Hills District, the glaze you choose ultimately shapes the character of the finished piece.

Australian potters are spoiled for choice, with independent suppliers offering imported and locally-mixed options, plus a growing community of makers who share their own recipes online. The climate, the rising popularity of home studios since the early 2020s, and a strong craft fair culture mean that you can find test tiles, lessons, and second-hand kilns across most capital cities. Before you commit to a bucket of anything, it helps to know what you are actually buying and how it will behave once it hits the kiln.

Understanding the major glaze families

Glazes are usually grouped into families based on their surface character and the temperature at which they mature. Earthenware glazes fire low, generally between cone 06 and cone 04, and tend to be brighter and more rustic. Mid-range stoneware glazes mature around cone 5 to cone 6 and offer the widest range of effects, from silky satin mattes to glassy transparents that pool beautifully at the foot of a pot. High-fire glazes, fired at cone 9 to cone 10, lean toward more muted, complex surfaces and are popular with reduction firers in studios like those around Bundoora or the JamFactory in Adelaide.

Within each temperature range you will find further divisions. Glossy glazes reflect light and exaggerate form, while mattes absorb light and tend to feel soft and powdery to the touch. Specialty glazes include crystalline varieties that grow dramatic starburst patterns during slow cooling, shinos that break across textured surfaces in patches of orange and rust, and ash glazes that reward those willing to slake and sieve their own wood ash. Thinking in families rather than colours helps because each recipe behaves predictably across an entire kiln load, even if the final hue varies with thickness.

Matching glazes to clay bodies

Even the best glaze can disappoint if it is paired with the wrong clay. A clay that is too vitreous at the glaze's maturity will slump or run during firing, while a clay that is too open may produce crawling or pinholing. Most Australian hobby studios sell a couple of standard stoneware bodies, like a buff or a white porcelain, and your supplier can usually tell you which commercial glazes they have tested on each. If you are working with a heavily grogged stoneware popular with hand-builders, look for glazes that tolerate toothy surfaces rather than ultra-smooth porcelains.

Test tiles are the cheapest insurance you will ever buy. A single 10-centimetre tile dipped, brushed, or sprayed with a candidate glaze tells you more in one firing than reading forum posts for an hour. Many local potters keep a folder of tile samples, written on the back with the clay body, the application method, and the cone reached, so they can recreate a favourite finish years later. It is also worth noting that locally-made clays, such as those mixed in regional Queensland, often behave slightly differently from imported porcelain, so testing at your own studio's kiln is essential rather than relying on the supplier's website photos.

Food safety and functional considerations

A glaze that looks gorgeous may not be safe for everyday use on a mug or dinner plate. Food-safe glazes must contain limited amounts of lead, cadmium, and barium, and should not leach acids from foods like coffee, citrus, or wine. In Australia, suppliers who sell glazes labelled dishwasher-safe and microwave-safe have usually tested them to relevant standards, although hobbyists are wise to apply a clear overglaze on functional rims if they have any doubts. Decorative pieces that will only be on a shelf can use a wider range of colours and finishes without the same scrutiny.

If you are making a set of espresso cups for a mate in Perth or a stack of cereal bowls for your own kitchen, durability matters as much as colour. Glazes that are too soft can be scratched by cutlery, while glazes that craze (develop a fine network of cracks) can harbour bacteria if they sit in moisture. The Australian food-safety regime for ceramics sold to the public is fairly strict, so a glaze sold for functional ware through a recognised retailer is generally trustworthy, but always confirm the label and avoid metallic lustres or bright copper-red glazes on interior food surfaces.

Working with Australian conditions

Climate shapes how glazes apply, dry, and fire, and Australia throws a few extra variables into the mix. Coastal humidity in Sydney or Brisbane can keep freshly glazed ware damp for hours, which delays drying and increases the risk of drips during handling. Inland studios around Ballarat or out towards Mildura deal with the opposite extreme, where a dry, warm day can pull moisture out of a greenware pot so fast that edges crack before you ever reach the kiln. Adjusting the studio routine, by running a dehumidifier, misting the air, or glazing earlier in the morning, often matters as much as the recipe itself.

Aussie kilns also vary wildly. Many backyard hobbyists use small test kilns from the 1970s that were rescued from school art rooms, while others have invested in new electric kilns imported from Korea or built their own gas kilns. Each behaves differently: an old top-loader with a sluggish controller may underfire certain glazes, while a modern front-loader with element-grade insulation can fire two cones higher than its gauge suggests. Tracking your cone packs and updating your firing log helps you know whether a glaze that looked dull should be re-tested one cone hotter. Several Aussie makers say that a quick chat with the potter you bought the clay from over a flat white beats a hundred hours of online research.

Application techniques and common pitfalls

How you apply a glaze changes everything. Dipping gives the most even coverage on a fully bisqued pot, while brushing suits textured pieces or detailed interiors where you want different colours on rim and body. Spraying, often done in a spray booth with an exhaust fan, gives softly blended gradations and is popular among production potters supplying shops like those along Sydney's Inner West craft trail. Whatever method you choose, consistent thickness is the secret: too thin and the clay body shows through, too thick and the glaze runs off the foot during firing and fuses your pot to the kiln shelf.

Common beginner mistakes include forgetting to wipe glaze off the foot, leaving fingerprints in the bisque that show through a transparent, and loading a damp pot into a hot kiln that can blow. A useful habit is to give every pot a final inspection under a raking light before it goes in, which catches stray brush marks and uneven rims. If something does go wrong and you want advice on recalibrating your studio routine, reaching out to a knowledgeable supplier can save months of trial and error, so it is worth contacting a glaze supplier who can recommend testing kits or troubleshooting steps. Eventually you will settle on a small palette of glazes that suit your clay, your kiln, and your aesthetic, and that is when the real fun begins.

Glaze family	Firing range	Surface character	Best for	Common pitfalls
Earthenware (low-fire)	Cone 06 to cone 04	Bright, often glossy, slightly soft	Decorative tiles, plant pots, children's pieces	Not waterproof unless sealed, limited colour depth on darker clays
Mid-range stoneware	Cone 5 to cone 6	Wide variety from glassy to matte, durable	Functional dinnerware, mugs, daily-use bowls	Some recipes craze on porcelain, can run on vertical surfaces
High-fire reduction	Cone 9 to cone 10	Muted, complex, often silky or textured	Vases, sculptural work, traditional teaware	Needs a gas kiln, harder to source in shared electric studios
Specialty (crystalline, ash, shino)	Variable, often mid to high fire	Unique visual effects, unpredictable variations	Show pieces, collectors, art-market work	Slow cooling schedules, larger test-tile budget, some surfaces are food-restricted