Basic pottery clay can be broken down into several categories that aren’t complicated but can be helpful and important to know when it comes to making your own pottery. What separates clay from mud is the purity and plasticity; in essence how much particulate is in the clay and how much unity there is at the molecular level. A good clay body has strong bonds that give clay what we call ‘plasticity’ the ability to stretch and form.
The classes of clay can broken down as follows:
The picture above shows the basics of what distinguishes each clay type and the uses for them, but each one is a unique body that people enjoy for different processes. For instance stoneware that are more groggy and have more grit to them could be good for larger projects, or for outdoor pots like planters. Earthenware might be nicely suited to vintage looking pots or to tableware and porcelains goof for tea sets, cups, or fine dinnerware.
So it really just depends on the person making pots – each clay has a unique body and they can be suited for certain tasks, but that is not to say that each one could be used for whatever you want.