What is the state of clay when it is referred to as "leather hard"?

When clay is described as "leather hard," it indicates that the clay is in a semi-dried state, where it has lost some moisture but still retains enough flexibility for certain modifications. At this stage, the clay is firm enough to hold its shape and is suitable for trimming or carving. Artisans often use this state to refine shapes, add textures, or implement decorative elements without risking damage to the piece, since it is more stable than wet clay but still workable.

The other states of clay described in the options contrast with the characteristics of leather-hard clay. When clay is completely dry, it becomes rigid and unalterable, while a liquid state would indicate it is still too wet to mold effectively. Lastly, clay that has been fired is no longer considered leather hard but rather bisque fired, characterized by its porous quality due to the initial firing process.