Depending on who’s asked, clay can either be a great resource or a sign of a problem. For gardeners, clay signals that their soil isn’t healthy enough to grow any crops, while a pottery lover sees clay as the ultimate tool of creation. Regardless, clay is an interesting natural phenomenon that can be found across the world and is made up of a variety of elements that make it uniquely suited for the creation of pottery. For those that want to know more about clay and how it functions, these are the most important points to remember.
The Composition of Clay
Clay soil is comprised of many millions of particles that are less than a millimetre in diameter. These particles are actually aluminium silicate that are the result of countless centuries of chemical weathering, leaving the particles embedded in the ground that we walk on every day. In fact, clay is the most abundant type of soil in the world, and makes up the majority of the earth’s land surface. These particles are spaced in tight formation, meaning that there’s a uniform amount of air between each particle within the soil. This gives clay its infamous inability to allow the free movement of both air and water, where the clay will instead absorb the water and swell during a process that’s known as cohesion.
Clay is also unique in that it has a certain degree of plasticity, which makes it perfect for pottery, as it’s easier to mould into different shapes and sizes.
The Clay Body
The clay body is the recipe that’s used to create the clay. It can either consist of a single type of clay, or up to a combination of ten different kinds of clay, which are amalgamated into a single form. Other types of materials can be added to the recipe, depending on what the intended outcome is. A good example is grog, which is a sandy material that adds stability and strength to the clay, while also reducing the amount of shrinkage that is experienced when the clay is being fired, and provides the perfect time for choosing games for your mobile. Another example is frit, which is added to the clay body, causing the clay itself to begin melting and fusing even at a lower temperature, and is usually added by artists that don’t have access to an industrial firing kiln.
The clay slip is a liquid clay that is often poured into a mould to create slip casts, which can then be used further down the production line to give ceramics special colours and textures.
The Colouring of Clay
Clay attains its colours through natural means and depends entirely on the types of chemicals that were present as the clay is forming. It can come in a range of different colours, from deep, rich reds, to pure whites. Iron is often added to increase the amount of red colouring in the clay, while stains and materials are included in the clay body to give the play a wider range of colours, which includes both reds and greens.