How to Glaze Pottery: A Beginner's Guide (UK)

What glazing actually does

Glaze is the glassy coating that turns a porous, fragile bisque-fired pot into a durable, waterproof and food-safe finished piece. It is a thin layer of finely ground minerals — silica, a flux to help it melt, and an alumina-rich stabiliser — suspended in water. When you fire it, that mineral coat melts and fuses to the clay, sealing the surface and giving pottery its colour, sheen and texture. Without a glaze firing, even a beautifully thrown pot will absorb water, stain easily and chip.

Glazing is the stage where most potters discover that ceramics is equal parts craft and chemistry. The good news is that you do not need to understand glaze chemistry to glaze well — you need a clean bisque pot, a well-mixed glaze, a sound application method and a kiln that reaches the right temperature. This guide walks through all four, in order.

Before you glaze: the bisque firing

Almost all glazing starts with a bisque firing (sometimes spelled "biscuit firing"). This first firing — typically to around 1,000°C, Orton cone 06–04 — hardens the clay enough to handle without it dissolving in the glaze bucket, while leaving it porous enough to draw the glaze water in and hold an even coat.

Glazing raw, unfired ("greenware") is possible but advanced; the clay is fragile and the glaze water can crack it. For beginners, bisque first, then glaze, then fire again. Both firings need a kiln that holds a steady, programmable temperature — this is why a reliable home pottery kiln is the single most important piece of equipment for anyone serious about glazing their own work.

Wipe the bisque ware free of dust before glazing. Any grease from your hands will resist the glaze and leave bare patches, so handle clean pots with clean, dry hands.

Choosing a glaze

Glazes are grouped in a few useful ways, and matching them correctly to your clay and kiln is what separates a good result from a ruined kiln shelf.

By firing temperature

• Earthenware / low-fire glazes mature around cone 06–04 (roughly 1,000–1,060°C). Bright colours, ideal for terracotta and white earthenware.
• Stoneware / mid- to high-fire glazes mature around cone 5–10 (roughly 1,180–1,300°C). Tougher, more muted, fully vitrified and very durable.

The cardinal rule: your clay, your glaze and your firing temperature must all match. A low-fire glaze taken to stoneware temperature will boil and run off the pot onto your shelf; a stoneware glaze fired too low will stay dry and rough.

By finish

Glazes come in gloss, satin and matt; transparent or opaque; and as specialist effects such as celadon, tenmoku, crystalline and raku. Underglazes are coloured slips painted on before a clear glaze and are the easiest way to add detailed decoration.

Food safety

If a piece will hold food or drink, use a glaze the manufacturer labels food-safe and fire it to its stated maturing temperature. Always choose lead-free glazes for functional ware.

Kiln Crafts specialises in the kilns that fire these glazes rather than the glazes themselves, so it is worth buying glaze from a dedicated ceramics colour supplier and noting the exact cone or temperature on the label before you commit a kiln load to it.

The four ways to apply glaze

There is no single "best" method — each suits different pots, glazes and batch sizes. Most potters use a combination.

1. Dipping

The fastest, most even method for production work. You submerge the whole pot in a bucket of well-stirred glaze for two to three seconds, then lift it out and let the excess drain. The porous bisque pulls the water in and leaves a uniform coat. Dipping needs enough glaze to fully cover the pot, so it suits potters making batches. Hold the pot with glaze tongs or your fingertips and touch up the small bare marks afterwards.

2. Pouring

Ideal for the insides of bowls, jugs and vases, and for larger pieces you cannot dip. Pour glaze into the pot, swirl to coat the interior, and tip the excess back out in one smooth movement. You can pour over the outside too, rotating the pot over a bowl or banding wheel to catch the run-off.

3. Brushing

The most accessible method for beginners and for anyone glazing small numbers of pieces, because it needs the least glaze. Brush-on glazes are formulated thicker for the job. Apply three even coats, letting each dry to the touch and brushing each layer at 90 degrees to the last for full, gap-free coverage. Brushing is slower and can show brush marks, but it gives you total control and is perfect for decoration and detail.

4. Spraying

Used for smooth gradients, large pieces and delicate blends, spraying gives the most even finish of all but needs a spray gun, a compressor and — importantly — a spray booth with extraction, because airborne glaze is harmful to breathe. It is the most equipment-heavy route and is generally a step beyond the home beginner.

How to glaze pottery, step by step

1. Stir the glaze thoroughly. Glaze settles in the bucket; the heavy minerals sink. Mix until it is the consistency of single cream with no sludge at the bottom.
2. Clean the bisque ware. Wipe off dust and avoid greasy fingerprints.
3. Wax the foot. Paint liquid wax resist onto the base and the lowest few millimetres of the pot. Molten glaze sticks to anything it touches, so an unglazed, waxed foot stops the pot fusing to the kiln shelf.
4. Apply the glaze by dipping, pouring, brushing or spraying. Aim for an even coat about the thickness of a postcard — too thin looks dry and patchy, too thick runs and crawls.
5. Clean the base. Sponge off any glaze that strayed onto the waxed foot. This is the most-skipped step and the most common cause of pots welded to the shelf.
6. Let it dry completely before loading the kiln.

The glaze firing

Load glazed pots so that no glazed surface touches another pot or the shelf — molten glaze will fuse them permanently. Leave a few millimetres between pieces. Many potters protect their shelves with a thin coat of kiln wash or place pots on stilts for low-fire work.

Fire to the glaze's stated cone or temperature, following the manufacturer's recommended schedule. A typical earthenware glaze firing climbs gently, holds at around 1,000–1,060°C, then cools slowly; stoneware climbs to 1,200–1,300°C. Resist opening the kiln until it has cooled below about 100°C — cracking the lid on a hot kiln thermal-shocks the glaze and can craze or shatter the work. Controlled, programmable firing is exactly what a modern electric kiln is built for, which is why the kiln you choose matters as much as the glaze.

No kiln yet? Some makers experiment with alternative low-temperature finishes while they save up — we cover the realistic options, and their limits, in our guide to firing pottery without a kiln. For genuine, durable, food-safe results, though, there is no substitute for a proper glaze firing in a kiln. If you are weighing up the investment, our breakdown of how much a pottery kiln costs in the UK sets out the real numbers.

Common glazing faults and how to fix them

• Crazing (a fine network of cracks in the glaze): the glaze and clay shrank at different rates. Match the glaze to the clay body, or fire slightly higher.
• Crawling (glaze pulls away leaving bare patches): usually dust, grease or too thick a coat. Clean the bisque and apply thinner, even layers.
• Pinholing (tiny pits in the surface): gases escaped too fast. Slow the firing near top temperature and add a short hold ("soak").
• Running (glaze pools at the foot or runs onto the shelf): coat too thick or fired too high. Apply less, and always wax the foot.
• Dry, rough finish: under-fired. Check your kiln reached the glaze's maturing temperature — a witness cone confirms what your controller claims.

A simple kit list for glazing at home

To glaze pottery at home you will want: a bisque-fired pot, your chosen glaze, a large mixing bucket, a sieve (80–120 mesh) for lump-free glaze, wax resist and a soft brush, glaze tongs, a sponge, and a home kiln capable of reaching your glaze's temperature. If you are throwing your own pots to glaze, a pottery wheel completes the home studio.

Frequently asked questions

Do you have to bisque fire before glazing?

For beginners, yes. Bisque firing hardens the pot so it survives the glaze water and stays porous enough to absorb an even coat. Single-firing raw glaze onto greenware is possible but advanced and far less forgiving.

How thick should the glaze coat be?

About the thickness of a postcard — roughly 1–1.5 mm. Too thin and the surface looks dry; too thick and the glaze crawls or runs in the firing.

Can you glaze pottery without a kiln?

Not with a true ceramic glaze, which only melts and fuses at kiln temperatures. There are cold-finish alternatives such as acrylics and food-safe sealers, but they are decorative rather than durable or dishwasher-safe. See our firing without a kiln guide for the honest pros and cons.

What temperature does glaze fire to?

It depends on the glaze. Earthenware glazes mature around 1,000–1,060°C (cone 06–04); stoneware glazes around 1,180–1,300°C (cone 5–10). Always fire to the maturing temperature printed on the glaze, and make sure your clay and kiln can reach it.

Why did my glaze come out rough and dry?

The most likely cause is under-firing — the kiln did not reach the glaze's maturing temperature. Confirm with a witness cone, and check the glaze was not applied too thinly.