White Low-Fire Glazes For Terracotta and Earthenware Clay – – Glaze Recipes
These glaze recipes are adjusted for once-firing / Raw Glazing at 1000 °C / 1832 °F / Cone 06.
They are wood-fired in this DIY updraft kiln:
/the-mediterranean-kiln-made-simple/
Burned up to 1000 degrees Celsius in about 3 hours, hold for 30 minutes, and down again in 3-4 hours.
The maximum temperature is more uneven than in an electric kiln. Object close to the flamepath may be hotter, objects close to the kiln walls may be cooler. But the measure is 1000 °C for 30 minutes.
Receipts and practical testing at the end of this article
If you’re making your own white low-fire glaze for terracotta and earthenware clay, chances are you are using materials from this list:
(Here I sum up the most commonly used, though it’s not a complete list)
Traditional mineral fluxes:
Colemanite
Gerstley Borate
Lithium Carbonate (small amounts)
Potassium Feldspar
For foodsafe glazes, avoid soluble fluxes; use frits instead
like commercial Boron Frits: Frit 3134 / 3124 / 3195 / 2962, etc.
Glass Formers:
Silica (Quartz)
Nepheline Syenite
Feldspar Soda (not a flux at low temperatures)
Stabilizers:
Kaolin (China Clay)
Calcined Kaolin
Ball Clay
Bentonite
Alumina Hydrate
Whitening / Opacifying:
Common food-safe opacifiers:
Zirconium Silicate
Tin Oxide (expensive)
Magnesium Carbonate (also a matte modifier)
Historically used:
Bone Ash
Titanium Dioxide
Talc
Other/Experimental:
Dolomite (satin/matte/ivory whites)
Strontium Carbonate (warmer / ivory)
Ilmenite (Used for rustic, speckled glaze surfaces)
A modern, safe glaze system can be:
Boron frit
Kaolin
Quarts
Zircon Opacifier
Base example:
50–70% Boron frit (like 3124)
10–20% Kaolin
5–20% Quarts
5–15% Zirconium Silicate
Traditionally, white glazes for terracotta were made with Tin.
Today, Tin is both a rare and expensive metal.
Testing how durable your glaze is:
- Lemon test: leave a lemon slice overnight
- Vinegar soak: 24h; look for matte/dull areas
- Dishwasher test: 10 cycles for wear
- Spoon or knife test: See if the wide side of the spoon makes gray “lines” on the glaze, or if the knife easily makes scratches
Remember that food-safe is not only about the components used to make the glaze, but also about the quality of the surface. Many of the glazes in this list can be food-safe as long as they are fluxed with a Frit and have an even, glossy surface without pinholes or cracks.
Also read:
/950c-ceramic-glazes/
/new-low-fire-ceramic-glaze/
In general:
- I have not been lucky with the Frit 2953.1; replace it with Frit 3124
- Tin oxide is particularly troublesome with once-fired glazes
- Magnesium Carbonate is more of a matt-maker than a white pigment
- Max 3% Magnesium Carbonate and 3% Tin oxide
All the tests:
White_x1000C_1
Name: Magnesium white
40 parts – P3124.1 Borosilikat Ferro fritte (first time with: High alkali frit P2962.1)
10 parts – Feldspar Soda
10 parts – Chalk
10 parts – Magnesium Carbonate
10 parts – Ball clay
I like it dry and thin; there are some problems when it’s thicker.
White_x1000C_2c
Name:
40 parts – P3124.1 Borosilikat Ferro fritte
5 parts – Magnesium Carbonate
20 parts – Quarts
10 parts – Kaolin
10 parts – Ball clay
Cracking when applied to thick. Magnesium gives a strong, white cover but also makes the glaze dry.
White_x1000C_2b
10 parts – Borax
20 parts – High alkali frit P2962.1
10 parts – Rutil
10 parts – Ball clay
30 parts – Quarts
10 parts – Magnesium Carbonate
Better, try again without Rutil and more flux
White_x1000C_2
Name:
20 parts – High alkali frit P2962.1
5 parts – Magnesium Carbonate
20 parts – Quarts
10 parts – Kaolin
10 parts – Ball clay
Good covering and a hard surface. I liked it even better when thick, where it is a combination of transparent and glossy, and white “snowflakes” in it.
White_x1000C_3b
80 parts – Gerstley Borate
20 parts – Talc
20 parts – Quarts
20 parts – Ball clay
Gases are released late in the melt, try to change Talc with Wollastonite.
White_x1000C_3
Inspired by: Antique White (creamy white)
From the book: Fired up with raku, by Irene Poulton.
80 parts – Gerstley Borate
20 parts – Talc
20 parts – Ball clay (not in the original receipt)
This receipt did not adapt well to raw glazing with a quick temperature change (3 hours 1000 degrees C).
White_x1000C_4
Tested like this:
70 parts – P3124.1 Borosilikat Ferro fritte
10 parts – Feldspar Soda
10 parts – Nephelin Syenite
10 parts – Ball clay
10 parts – Zircopax (mixed wrong, used Zirkonium Oxid)
5 parts – Rutile
WTF… let’s hope Logan doesn’t take this as an insult, the glaze did not like my adjustments, my fault alone.
The original receipt:
Logan Wall’s Bills basic liner (white glossy
From the book: Low-Fire Soda by Justin Rothshank.
65,8% Ferro Frit 3124
17,1% Kona F-4 Feldspar
6,5% Nephelin Syenite
10,8% Kaolin
Additives:
14% Zircopax
0,5% Rutile
2% Bentonite
White_x1000C_5
Chris Gustin White
From the book: AMAZING GLAZE by Gabriel Kline.
40 parts – P3124.1 Borosilikat Ferro fritte
30 parts – Gersley Borate
25 parts – Nepheline Syenite
5 parts – Quarts
8 parts – Zircopax (mixed wrong, used Zirkonium Oxid)
10 parts – Ball clay (not in the original receipt)
I like this, some pinhols, a bit stiff melt
White_x1000C_6b
50 parts – Gerstley Borate
10 parts – Wollastonite
10 parts – Zinc Oxide
10 parts – Bentonite
20 parts – Kaolin
20 parts – Quarts
10 parts – Zircopax
I like this; it melts well, low glaze surface tension, works ok as both thick and thin, strong glossy surface. Low green strength and can crack when drying.
White_x1000C_6
Zinc Oxide Gray
50 Gerstley Borate
20 Kaolin
20 Quarts
10 Wollastonite
10 Zinc Oxide
10 Bentonite
I like this, it melts well, not too runny, no pinholes, next try adding Zircopax
White_x1000C_7b
Zirconium White
70 parts – P3124.1 Borosilikat Ferro fritte
10 parts – Sodium Carbonate
10 parts – Wollastonite
10 parts – Chalk
20 parts – Quarts
10 parts – Ball Clay
10 parts – Zirconium Silicate (Zircopax)
Better, reduced the high surface tension by using another flux, but still not there.
White_x1000C_7
Zirconium White
50 parts – P2953.1 Boraks Fritte (E)
10 parts – Sodium Carbonate
10 parts – Wollastonite
10 parts – Chalk
20 parts – Quarts
20 parts – Kaolin
5 parts – Bentonite
10 parts – Zirconium Silicate (Zircopax)
Failure, nice white color
White_x1000C_8c
Name: White Gloss Base
40 parts – Gersley Borate
20 parts – Nepheline Syenite
10 parts – Chalk
60 parts – Quartz (to reduce shrinking)
10 parts – Molochite (to reduce shrinking)
10 parts – Ball clay
5 parts – Tin Oxide
Not what I expected
White_x1000C_8b
Name: White Gloss Base
40 parts – Gersley Borate
10 parts – Nepheline Syenite
10 parts – Chalk
30 parts – Quartz
10 parts – Ball clay
5 parts – Tin Oxide
Interesting, less glossy, but it can relate to differences in temperature, still surface tensions, it changed character.
White_x1000C_8
Name: White Gloss Base
20 parts – Gersley Borate
20 parts – Feldspar Soda
10 parts – Nepheline Syenite
10 parts – Chalk
20 parts – Quartz
10 parts – Kaolin
10 parts – Ball clay
5 parts – Tin Oxide
A disaster! But a starting point. Nice when thick, high tensions. Remove Feldspar and Kaolin?
White_x1000C_9c
Name: Semi-glossy white
30 parts – Gersley Borate
30 parts – Colemanite
10 parts – Dolomite
40 parts – Quarts
10 parts – Ball clay
5 parts – Tin Oxide
Trying less clay and more quartsto reduce surface tension, and more flux to make a stronger melt. Not better at all.
White_x1000C_9b
Name: Semi-glossy white
20 parts – Gersley Borate
20 parts – Colemanite
10 parts – Dolomite
20 parts – Quart
20 parts – Ball Clay
5 parts – Tin Oxide
Better! Have problems with pinholes, but holding the maximum temperature longer or adding more flux may fix it. I’m going to use this as-is for non-tableware.
White_x1000C_9
Name: Clean White
20 parts – Gersley Borate
20 parts – Colemanite
20 parts – Feldspar Soda
10 parts – Dolomite
20 parts – Quart
10 parts – Kaolin
20 parts – Ball Clay
5 parts – Tin Oxide
A disaster! But a starting point. Better melt, remove Feldspar and Kaolin?
White_x1000C_10
Name: White test
50 parts – Borax fritte P2953.1
10 parts – Talc
10 parts – Chalk
30 parts – Quart
10 parts – Kaolin
Low greenstrength, easily falls off when dry. A funny failure. I won’t look in this direction anymore.
White_x1000C_11b
Name: Bonewhite
60 parts – P3124.1 Borosilikat Ferro fritte
30 parts – Talc
10 parts – Wollastonite
30 parts – Quarts
20 parts – Ball clay
Cracks when applied to thick, dry, but the glaze fit is not too bad. Dry and boring, changed character with the 3124 flux.
White_x1000C_11
Name: Bonewhite
60 parts – Borax Frit P2953.1
30 parts – Talc
10 parts – Wollastonite
20 parts – Ball clay
30 parts – Quarts
Strange glaze, not what I expected, swap to another Frit, reduce Wollastonite to 5?
White_x1000C_12
Name: My best white
60 parts – P3124.1 Borosilikat Ferro fritte
10 parts – Chalk
10 parts – Kaolin
10 parts – Ball clay
30 parts – Quarts
Nice white glaze, needs some adjustments
White_x1000C_13c
Name: Bead White
20 parts – P3124.1 Borosilikat Ferro fritte
30 parts – Gerstley borate
10 parts – Magnesium carbonate
10 parts – Chalk
50 parts – Quarts
10 parts – Ball clay
White_x1000C_13b
10 – Gerstley borate
20 – High alkali frit P2962.1
20 – Magnesium Carbonate
10 – Chalk
10 – Kaolin
30 – Quarts
I like it, but it’s too dry; the cracks relate to how the glaze was applied. Over-fired with maybe 150 degrees
White_x1000C_13
Inspired by: “Bead White” lindaarbuckle.com/lowfire-glaze-recipes
Name: Bead White
10 parts – Borax (was 20)
40 parts – Gerstley borate
30 parts – Magnesium carbonate
30 parts – Quarts
20 parts – Ball clay
10 parts – Zircopax
Did not mix in the Borax properly, and it melted in separate spots. I like the dry areas.
White_x1000C_14
Inspired by: Crackle White lindaarbuckle.com/lowfire-glaze-recipes
Name: Crackle White
50 parts – Gerstley borate
10 parts – Rutil light
20 parts – Quart
20 parts – Ball Clay
10 parts – Zircopax
White_x1000C_15
Name: Zircopax glaze
20 Gersley Borate
20 Colemanite
10 Talc
20 Ball clay
20 Zircopax
White_x1000C_16
Name: Matt white
40 Gerstley borate
10 Lithium carbonate
10 Nepheline syenite
40 Quarts Flint
20 Ball clay
20 Magnesium carbonate
5 Tin oxide
White_x1000C_17
Inspired by: “Slip Bisque Mills Earthenware” lindaarbuckle.com/lowfire-glaze-recipes
Name: Slip Bisque Mills
20 Ferro frit 3124
10 Ball clay
10 China clay
20 Calcined kaolin
20 Talc theoretical
20 Quarts Flint
10 Zirconium silicate
White_x1000C_18
Inspired by: “Velvet Crust Al Oxide” lindaarbuckle.com/lowfire-glaze-recipes
Name: Zircopax glaze
50 Gerstley borate
10 Nepheline syenite
30 Alumina
30 Quarts
20 Ball clay
10 Zirconium silicate
Also read:
https://www.alfredgrindingroom.com/recipes
White Low-Fire Glazes for Terracotta and Earthenware Clay – 2026