The Best Glazes for Terracotta — Spinning Pots
Terracotta is a beautiful and classic form of pottery, which is quite popular all over the world. The identifiable characteristic of terracotta pottery is its typical reddish-brown colored body with a porous clay texture. Terracotta clay is used as the base for producing this type of potteries. The presence of iron in the clay, which gets fused with oxygen present in the air is responsible for the attractive red color of the clay.
The beauty of terracotta pottery lies in its natural brown appearance, decorations carved on its body, and shiny transparent glaze applied on its surface. The worldwide popularity of glazed terracotta potteries is massive. They are even quite useful for household kinds of stuff. So, in case you are planning to let your hands get involved in doing some terracotta art on your known, then this article is apt for you.
Well, glazing a terracotta is pretty different from ceramic wares. Are you wondering what makes terracotta different from ceramics?
Here is your answer.
Since the real flavor of terracotta pots lies in its reddish-brown color, you can either opt for glazing it with some other color or leave it to remain unglazed, according to your choice. Some prefer to leave it unglazed to let the authenticity of the terracotta clay remain intact. Whereas, some like to glaze terracotta clay piece to increase its durability.
Unglazed terracotta pots are porous and absorb water, whereas glazing is used to make it waterproof, and capable of rough use. There are multiple types of glazing that you can use for decorating your terracotta pot. Some artists prefer to use a coat of transparent glazing to restore the natural look of the red terracotta body. At the same time, a few people, especially beginners like adding their touch of decorativeness to create some unique look by applying other colored glazes.
So, here we will be talking about the glazes that you can use for customizing your terracotta pot. But before that, let us tell you the basics about choosing the right glaze for you. Trying your hands in terracotta pottery making is a great thing to do. You can use DAS air hardening modeling clay terracotta color for a better experience.
Things to consider before choosing the right glaze for your terracotta pot:
Glaze refers to a type of glass, which is melted during glazing. It is created by mixing particular ingredients while maintaining the right ratio. This melted glass is made to glue onto the pottery surface to add an extra layer of protection to increase the durability of the pot and give some touch of beauty. The melted mixture becomes stiffer when it gets cold. Here is what you should look for, in a glaze, before choosing one for your next project.
The idea of glazing is followed by the idea of adding colors to your pottery surface. Glazing comes in a broad range of colors. There are various oxides, chemicals, and frits available to add coloration to the glazing mixture. Adding colorants or pigments to create solid and vibrant colors through glazing is what you can do on your pottery to give it a striking change.
Colorants like iron oxides, copper oxides, chromium oxides, cobalt oxides are used mostly. Besides, the kiln atmosphere, oxidation, and reduction processes do the rest of the job in influencing the color of the glazed pottery. So, you will have to understand the change of color in different conditions, and the rest is up to your flexibility for experiments.
The very name “glazing” might make you associate it with a glossy or glittery finish. But that is exactly where you make a wrong assessment of the texture of glazing. The surface quality of glazing can range from glossy, glittery, and shiny to matte, dry, and satiny. The texture quality entirely depends upon the ingredients used for making the glazing solution and their amounts. You can also achieve a rough quality texture with some special kind of glazing if you want.
Glazing also has multiple ranges of opacity. It can have a transparent type of texture or a complete opaque consistency. The presence of tiny particles in the glazing mixture, or sometimes, trapped air bubbles are responsible for affecting the opacity of the glaze. For example, some of the white glazings look white and not transparent because of its high opacity. Besides these, the presence of minerals in the glazing compounds and their nature of forming crystals can be the reason behind opaqueness.
So, before using a glaze for your terracotta clay, you need to understand the exact nature of opacity present in your glazing mix. It will help in achieving the right texture for your pottery, exactly the way you want.
Just like us, glazes also have their type of tantrums. But you know, the only best way to handle tantrums is to understand it properly. All glazes don’t react in the same way at the same temperature. There are specific melting ranges for every glaze. The melting temperature of a particular glaze might not mature or fully melt at the same temperature as that of another kind of glaze.
A small range of fire is not sufficient for melting glazing. Again, too much of firing makes the glaze too much fluid, which is hard to handle or work with. Besides, the kiln atmosphere also influences the fluxing of glazes. So, you need to become well acquainted with the temperature ranges of a particular glaze that you are using to understand its nature thoroughly.
Once you are done focusing on all the factors mentioned above, you can thereupon choose the right glaze for your terracotta pottery. Now, we will let you know about the different types of glazing that you can use for your upcoming terracotta project.
Glazing that you can use for your terracotta pottery:
There are 3-main types of glazes, which you can use on your terracotta clay piece. These basic glazings can be customized in the way you want by adding different compounds, colorants, or chemicals. Following are the types of glazes that you can use for decorating your terracotta pots:
1. Lead-Free Earthenware Glazes:
The earthenware lead-free glazes are used for making pottery pieces, food, and drink-safe. You can add multiple ranges of colors by adding colorants or other chemical compounds in these glazes. Also, you can create your customized shades to create some of the beat glazing designs. The little amount of lead present in it only does the job of making the glaze durable enough. This minimal amount of lead is not at all toxic and is fine for making the pottery food-safe. It is quite popular among the potters for the glazing crockery set.
You can easily create a low-fire food-safe glaze for your earthenware as well as terracotta pots, by following a few simple steps-
You will require a few ingredients as follows:
- 34g of sodium silicate
- 10lbs of OM4 ball clay
- 5 gallons of water
Take a bucket first. Then, take 2.5 gallons of water, and mix 34g of sodium silicate and 10lbs of OM4 ball clay in it. Leave the mixture to sit overnight.
Check after 12–24 hours if the mixture has settled properly. There will be the formation of a sediment layer, which will make you understand that the mixture has settled properly. If not, then let it stay idle for some more time, and wait until it settles completely.
When the mixture is entirely ready, you need to take away the top half portion of it. Don’t disrupt the entire mix, while you take off the top half. The milky texture of the above part is what you are going to use for glazing your pot.
Here are few more food-safe glazing recipes for your earthenware that you can use on terracotta pots too.
2. Fritted Lead Contained Earthenware Glazes:
A particular amount of fritted lead is often added to the earthenware glazes to obtain the required glazing mixture for decorating items. The usage of white and red lead is quite popular in making this glaze for decorative items like flower vase, showpiece, etc. But this kind of glaze is not safe for use on the pots meant for food storage purposes. The glazing is added with the white and red lead along with bi-silicate frit to make the mix capable of resisting acidic materials.
Here is an easy lead-frit glaze recipe for you, which you can follow to make your own homemade glaze.
You need to prepare the frit first before moving onto the next step. So, you would require the following ingredients in the proportions necessary to make the frit:
- Quartz- 26.10g
- Kaolin- 4.00g
- Whiting- 10.30g
- Red lead- 17.80g
- Boric acid- 16.40g
- Soda ash- 3.00g
- Potash feldspar- 22.40g
First, take a bucket for making the frit. You might need a pair of gloves and a face mask for protecting your hands and face from these chemicals. Mix all the ingredients carefully and let it sit for 12–24 hours. Once they are ready, you need to start preparing the glaze.
Now, to make the glazing, follow the given method accurately.
You need to mix the frit along with Kaolin carefully. Then, leave the mixture to sit overnight. After this, take your terracotta piece, apply the glazing, and leave it aside for some more time. Finally, fire it at 1000°C temperature to let the glaze stuck onto the pot’s surface permanently.
3. Stoneware and Mid-Fire Glazing:
These kinds of glazes have a distinct characteristic of tolerating high intensity of firing. A large option of color palettes can be used in this type of glaze to make multiple shades and designs. They have the flexibility to get inter-mixed and create a new kind of glazing that can be applied to both ceramic wares and terracotta. If you are willing to work with numerous types of glazing to create a project, then stoneware or mid-fire glazing will be apt for you. It creates beautiful effects when fired together.
Here we are going to discuss two recipes for stoneware glazing. Have a look.
- Recipe for pale violate blue glaze:
- Whiting- 21%
- Potash feldspar- 27 %
- Quartz- 32%
- China clay- 20 %
- Neodymium oxide- 5%
You need to mix the first four ingredients, and then whisk the mixture properly. In the meantime, add Neodymium oxide to the mixture. Let the mix stay settle for a few hours or overnight. Check if the mixture has settled. Whisk again before applying it to your terracotta pot. However, keep in mind that this glaze needs to be fired at 1280°C temperature at the oxidized cone-9 range to achieve the exact color.
Grab the first five ingredients and blend them properly until all lumps get dissolved. After you are done with mixing them properly, add 0.5% of copper oxide along with 0.1% of cobalt oxide in the previous mixture. Then, blend them properly. After that, let the mixture sit for 12–24 hours.
Check if the mixture has settled. If not, then let it settle for a few more hours. Once you are done with settling the mix, whisk it again, and apply the glaze on your terracotta pot. This mixture is perfect for firing at 1260°C temperature at the reduction range of cone-8 to obtain the ideal color.
Types of glazing based on surface texture:
Depending on surface texture, you can create different kinds of glazing effects on your terracotta pot. Following are given some of the effects that you can use for glazing your terracotta pottery pieces by changing the glazing recipe:
To get the perfect satin-like smooth, yet not-so-glittery or glossy texture, you need to apply the right kind of glazing compounds. It is going to look great on your terracotta pottery. For those who love to decorate their pottery with minimal, yet classy decorations, this satin matte glazing is perfect for them. You can create multiple ranges of colors with this effect. Here, we have highlighted a particular satin matte glaze recipe.
Satin white matte glaze recipe:
- Soda frit (Ferro 3110)- 20%
- Soda feldspar (NC -4)- 18%
- Zirconium opacifier- 24%
- Dolomite- 14%
- EPK- 10%
- Spodumene- 14%
Blend all these ingredients, apply it to the pot, and make the mixture fire at the oxidation cone range of 6.
Those who want to add some extra gloss to everything they love, the glossy glaze is perfect for them. The beautiful glossy texture gives a nice appearance to your dull and rough terracotta pottery body. It is more like giving a new life to your ordinary terracotta piece to make it an extraordinary one.
Besides, the glossy glaze creates a beautiful color effect on the terracotta body, which makes light reflect on it. Choosing a glossy glaze recipe and adding your favorite color to it is the best thing that you can do to your pottery piece. The glossy glazing is quite durable enough and looks fantastic on anything. Here is a glossy glaze recipe we are sharing with you; you can give it a try.
Sapphire blue glossy glaze recipe:
- Frit- 39.2g
- Silica, quartz, flint- 13.4g
- Custer feldspar- 23.5g
- EPK, EP Kaolin, Edgar plastic- 23.5g
- Cobalt carbonate- 2g (approx.)
- Rutile- 4g (approx.)
This glazing recipe needs to be fired at the oxidation range of cone-6.
Add some extra shine to your dull terracotta pot by giving some glittery glow to it. Adding shiny and glittery textured glazing is quite popular in the pottery world, and it looks great on any kind of clay piece. Not only it accentuates the beauty of the pottery artwork, but also adds a bit of extra gloss to it. If you are planning to decorate your terracotta piece in a way to make it strikingly shiny to the eyes and increase the beauty of your home décor, then the glittery glaze is your thing.
Try some glittery glaze to embellish your terracotta pot and get mesmerized by its stunning new look. Here is a glittery glaze recipe that you can opt for, to make your terracotta pottery piece look incredibly gorgeous.
Black pearl glittery glaze recipe:
- Feldspar- 62g
- Silica, quartz, flint- 9g
- Manganese dioxide- 19g
- Whiting, calcium carbonate- 2g
- EPK, EP kaolin, Edgar plastic- 5g
- Bentonite- 2g
- Talc, magnesium silicate- 2g
Prepare the glittery glaze by whisking all these ingredients and fire it at the oxidation neutral reduction range of cone-10.
Does your pottery piece seem to be a mere pot of clay? Well, now, you can turn it into a metallic one. No, of course not into real metal. But you can easily create a metallic effect on your clay pot. The metallic effect is an amalgamation of all the other effects; so, it seems to be glossy, glittery, yet possess a bit matte texture.
The metallic texture on your terracotta pottery will not only make it look extraordinary but also give your interior a classy, luxurious look. The metallic glaze is worth trying to enhance the beauty of your simple terracotta pot. Here is a recipe for creating a metallic effect on your favorite terracotta piece. Try it on your own.
Gold metallic glaze recipe:
- Manganese dioxide- 36.5g
- Ball clay- 4g
- Flint- 4g
- Black copper oxide- 4g
- Redart clay- 49g
- Cobalt oxide- 2.5g
Blend all the above-stated ingredients to form a metallic glazing mixture. Then, fire it at the oxidation cone range of 6.
Apply under glazing and transparent glaze to your terracotta pot:
Though there is plenty number of glazing recipes providing different effects and colors that you can experiment with, going simple is also a good idea. Using a clear and transparent glaze is always simple, yet the best idea to decorate your terracotta pottery piece.
You can glaze it in some different or customized way. Using an underglaze to decorate your terracotta pot, and then finishing it up with a clear glaze is the easiest yet the prettiest thing that you can do to your pottery artwork. So, here we have provided some under glazing techniques that you can apply on your terracotta clay piece.
There are many more ways to underglaze your terracotta clay piece in a smart, beautiful, and innovative approach. Just keep trying new methods every time, and you’ll be able to create magic with your hands.
Here is a recipe for a clear, transparent glaze that you can use to make a top coat after applying under glazing on the terracotta pottery surface. You can also apply this glaze on your bare terracotta pot to restore the natural reddish-brown terracotta look with a glossy and waterproof coating. This glazing mixture is good to use at the oxidation range of cone-6.
Whether you create beautiful surfaces by decorating terracotta pots with different types of colorful or solid glazing, or leave it simple with a clear glaze, that entirely depends on your choice. There are no routine bound rules for glazing. And it is quite enjoyable to work with different colors and effects to achieve perfection and uniqueness at the same time.
The glazing techniques mentioned above, along with the recipes, are going to help you to get an idea of the basics about terracotta glazing. To ace the glazing game, go on creating by adding your extraordinary authentic touch and trying something new every time. We hope this content will help you with your next terracotta project.
Originally published at https://spinningpots.com on August 7, 2020.