Would you be able to differentiate between glazed and unglazed tableware and which option would be better? Do you know what glaze is used for in ceramic tableware? Do you think that glaze is only decorative or do you buy tableware based on whether its glaze is utilitarian or not?
Well, in this post we are going to learn a little more about ceramic glazes, what they are used for and which is the best option for your tableware.
First of all, let’s remember the process of making a ceramic piece:
- As we learned in our previous post, ceramic pieces are made with different types of clay. They are created with different pottery techniques, such as the traditional potter’s wheel that we use in our atelier, just like we have learned from the local potters of La Rambla in the last century.
- When the pottery pieces are dry, a first firing is carried out, called bisque. In this firing, our plates go from being made of clay to being made of ceramic. Did you know that ceramic literally means “clay that has been fired”? That is why we do not call a piece “ceramic” until it has had its first firing.
- After the bisque firing, these pieces can be decorated in different ways using glazes and oxides. This is the work of the ceramist. Normally, glazes are composed of different ingredients that are mixed with water and applied to the pieces in a liquid state: by bath, with a spray gun, with a brush, etc. In our studio, all our tableware is painted and glazed by hand.
- The already glazed pieces return to the kiln, this time for the glaze firing. After that, they emerge with their final finish and their definitive colours.
Why are the pieces glazed?
Good question. But it must be clarified that not all ceramic pieces are glazed. There are pieces that are finished in the first bisque firing.
Therefore, to answer this question we need to classify ceramics between:
- Low temperature ceramics: those made from clays such as white clay or terracotta, and fired at around 980ºC or 1000ºC. Low temperature ceramics are porous and therefore, when liquid is poured inside, it ends up filtering and coming out. This is what happens with the the Spanish called “botijo” (Cooling summer jug) and that allows it to cool down, which is why we should never glaze it. However, if we use low temperature ceramics to make jars, containers or tableware, we need to glaze the pieces to make them waterproof.
- High temperature ceramics: those made from pastes such as stoneware and porcelain and fired between 1200ºC and 1300ºC. The kitchenware and tableware made from these materials vitrify by themselves at their firing temperature, so they do not need glaze to prevent food from filtering through. However, in these cases, we glaze to make the piece even harder, to make it more sanitary and cleaner, or just to give it a specific finish, decoration or texture.
What types of glaze are there?
In addition to the classification of glazes according to their temperature, we can find other characteristics that define them:
On the one hand, we can look at their composition, that is, the main ingredient they use as a flux material to vitrify in the kiln. Thus, there are lead glazes (which mainly use lead) or alkaline glazes (which mainly use alkalis such as sodium, borax, etc.). This very technical information is often used in factories but does not usually reach the customer.
On the other hand, we can differentiate them according to their final appearance:
Shiny or matte.
Opaque or translucent.
Coloured or transparent (without colour).
So, which glaze is best for my tableware?
Having said all the above, a first conclusion is that tableware is always better with glaze. The suitability of one glaze or another often depends on the use of the piece. In our case, if we want to have a beautiful set of plates that is also utilitarian, we have to take into account the following tips:
- High-temperature glazes are harder and more resistant, which is why we recommend buying stoneware dinnersets like those we make by hand at Torres Ferreras. These glazes also do not tend to crack or deteriorate over time. And most importantly, they do not chip or break easily in the dishwasher or in domestic use at home. You can have a handmade, artisanal set of tableware that has a special soul and use it every day without having to worry about it deteriorating. Don’t keep it only for ‘special occasions’ that may never come! If you don’t believe us just by saying, then watch it in the following video:
- Lead is the main flux used in low-temperature glazes. However, lead volatilizes and disappears above 1200ºC, which is why it is not found in high-temperature glazes. So again, although the lead content of commercial low-temperature glazes is usually within EU accepted levels, a stoneware plate is much more sanitary from a food safety point of view and is a safe bet for restaurant or hotel tableware.
- Shiny glazes are usually cleaner and more sanitary than matte glazes, which tend to have a bit more texture where food can stick to. However, most of the glazes we call matte, for example in our collections, are actually satin and ensure a good melting of the glaze which makes it totally suitable. Also, a high-temperature matte piece is more suitable because it can be cleaned at a higher temperature or with greater care without damaging the glaze.
- The style, colour and decoration is a matter of personal taste. However, it is true that in artisan workshops like ours we make our own glaze recipes that ensure greater originality and, above all, versatility to create different finishes according to the client’s requests for their home, shop or restaurant.
In conclusion, our glazes make our plates end up being beautiful, utilitarian, original, 100% handmade and with history and tradition. They are also very sustainable, since we use as many local products as possible for their creation, making them very durable and timeless.
You can buy our tableware online on the Shop page, but in case you decide for other brand, we hope that at least this post has helped you choose any other tableware with a little more technical knowledge 🙂
