# How to Make Ceramic Glaze From Raw Materials

URL: https://myclay.online/blog/how-to-make-ceramic-glaze
Published: 2026-08-18
Category: Glazing
Tags: Glazing, Materials, Technique
Reading time: 5 min

> Weigh dry materials to a recipe by percentage, add water to roughly 80 percent of the dry weight, blend, sieve twice through 80 mesh, and fire test tiles before committing a batch to real pots.

Mixing glaze is weighing powders into water. It is not difficult, but it is unforgiving of sloppiness — a recipe is a set of ratios, and small errors compound into a glaze that behaves nothing like the one in the book.

> **From the studio:** The best habit I ever picked up was ticking off each line of the recipe with a pencil as it went into the bucket. I lost a 10 kg batch once to a doubled silica addition that I could not detect until the tiles came out dry and unmelted, and a pencil mark would have caught it in a second.

## What you need

- **A digital scale** to 1 g for a 5 kg batch, plus a jeweller's scale to 0.1 g for colourants.
- **Buckets with tight lids**, ideally in a size that leaves headroom for blending.
- **An 80-mesh sieve** and a stiff brush to push material through.
- **A respirator** rated for fine particulates — a paper dust mask is not adequate for silica.
- **A dedicated surface** you can wipe down wet.

## Safety first, because this part is real

Glaze materials are dry mineral powders. The main hazard is **silica dust**, which causes irreversible lung disease with long-term exposure. Barium, lithium, manganese and several colourants carry their own risks.

The rules are simple and non-negotiable:

- Wear a fitted respirator whenever a powder is open.
- Mix in a ventilated space, ideally not your kitchen.
- **Never sweep or dry-brush.** Sweeping puts settled dust back in the air. Wet-mop or use a HEPA vacuum.
- Wipe surfaces down wet at the end of every session.
- Keep food, drink and children out of the space.

None of this makes glaze mixing dangerous in itself. Ignoring it over years is what causes harm.

## Reading a recipe

A glaze recipe is written in percentages that add to 100. Colourants and additives sit outside that total and are written as "plus" amounts.

```
Satin White — [cone](/blog/cone-6-vs-cone-10) 6
Custer feldspar     40
Silica              22
Whiting             14
EPK kaolin          14
Talc                10
                   ---
                   100
+ Zircopax           8
+ Bentonite          2
```

To make a batch, pick a total dry weight and treat percentages as grams. 5000 g total means 2000 g of feldspar, 1100 g of silica, and so on. That is the whole calculation.

<Diagram />

## Mixing, step by step

1. **Weigh the water first.** Roughly 80 g of water per 100 g of dry material is a good starting point for a dipping glaze. Put it in the bucket before the powders — adding water to dry powder creates far more airborne dust.
2. **Weigh each material and add it.** Tick each line off the recipe as you go. Getting distracted and adding silica twice is the classic failure, and it is unrecoverable.
3. **Add bentonite differently.** It clumps stubbornly. Mix it dry with a scoop of another powder before it goes in.
4. **Let it slake for 10 minutes.** The clay materials need to absorb water before blending.
5. **Blend.** A drill with a paddle for large batches, a stick blender for small ones.
6. **Sieve twice** through 80 mesh, pushing material through with a brush. This is not optional — unsieved glaze gives speckles, pinholes and blisters.
7. **Adjust the water.** Aim for single cream, thin enough that you can just see your fingerprint through a coating on your finger. Add water in small increments; you cannot easily take it out.
8. **Label the bucket** with the recipe name, the cone and the date, in permanent marker.

## Test before you trust it

Dip test tiles, fire them to your cone, and look at them properly before glazing thirty pots.

A good test tile is **L-shaped or bent**, so it shows both a vertical and a horizontal surface. Vertical tells you whether the glaze runs; horizontal tells you how it pools. Dip one end twice to show the effect of double thickness.

Check for:

- **Running** — did it move down the vertical face?
- **[Crazing](/blog/glaze-crawling-causes-and-fixes)** — a fine crack network, visible when you rub ink into the surface and wipe it off.
- **Pinholes and blisters** — usually too thick, fired too fast, or unsieved.
- **Fit** — does it flake at the edges (shivering) or craze?

## Adjusting

- **Too glossy** — increase alumina, usually by adding kaolin, in 2 percent increments.
- **Too matt or dry** — the melt is insufficient; increase the flux or reduce silica slightly.
- **Crazing** — the glaze contracts more than the body. Increase silica or reduce the high-expansion fluxes (sodium and potassium).
- **Running** — increase alumina and silica, or apply it thinner.

Change one thing at a time, and record every change with its test tile. A binder of tiles with recipes on the back is the single most valuable thing in a glaze studio.

## Storage

Sealed buckets keep indefinitely. Glaze settles hard — a bucket untouched for six months will have a solid layer of flux at the bottom, so stir all the way down before every use. If a batch has dried out, add water and re-sieve rather than throwing it away. Nothing about a mixed glaze goes off.

## Where to get recipes worth mixing

A recipe is only as good as its testing, and there is a lot of untested material circulating.

**Published collections.** Books and the ceramics magazines publish recipes that have been fired by more than one person. Start there.

**Supplier recipes.** Many suppliers publish recipes formulated around materials they actually stock, which removes the substitution problem entirely.

**Studio recipes.** If you work in a shared studio, their buckets have been fired hundreds of times in the kiln you are using. That is more valuable than any published recipe.

**Online forums and social media.** Treat with care. Materials vary by region and by brand, and a recipe that works with one supplier's feldspar may not with another's.

Two cautions worth carrying into any recipe. First, **check what is in it before you mix it** — barium carbonate, lithium compounds and some colourants have real handling and food-safety implications. Second, **a recipe is a starting point, not a result.** Your kiln, your schedule, your clay body and your application thickness all change what comes out, which is why the test tile always comes before the batch.

## Where to go next

The chemistry behind those adjustments is in [what is ceramic glaze made of](/blog/what-is-ceramic-glaze-made-of). For application once it is mixed, see [how to glaze pottery at home](/blog/how-to-glaze-pottery-at-home). And if you would rather buy than weigh, [where to buy pottery glaze](/blog/where-to-buy-pottery-glaze) compares the formats.

## Frequently asked questions

**Is it cheaper to mix your own glaze?**

Substantially, once you use more than a few litres a year. Raw materials in bulk cost a fraction of jarred commercial glaze per litre. The trade-off is the scale, the storage, the sieve and the testing time.

**What equipment do you need to mix glaze?**

A digital scale accurate to 1 g (0.1 g for colourants), buckets with lids, an 80-mesh sieve, a stiff brush, a respirator rated for fine dust, and a dedicated space you can wet-clean.

**Can you mix glaze without a kiln?**

You can mix it, but you cannot use it. Glaze only becomes glaze in a firing. Without a kiln of your own, work with a studio that will fire your pieces.

---
Source: https://myclay.online/blog/how-to-make-ceramic-glaze — https://myclay.online/