A process in which pieces of one material are fitted into recesses in another material to create a design, pattern, image, or contrasting surface.
Inlay is a process in which pieces of one material are inserted into a larger piece of another material to create a design. In sculptural and architectural work, stone may be inlaid with contrasting stone, metal, glass, shell, or other durable materials.
The receiving surface is cut or prepared so that the inserted material fits securely and, depending on the intended effect, may finish flush with the surrounding surface or remain slightly proud. Historical stone traditions include highly sophisticated geometric and pictorial inlay.
Etymology
English in + lay, referring to material laid or set into another surface.
Sculptor Notes
Successful inlay depends on accurate fitting, compatible materials, and an understanding of movement, adhesion, polishing, and long-term exposure. In stonework the joint itself becomes part of the craftsmanship and should be designed as carefully as the inserted form.
References
https://www.getty.edu/vow/AATFullDisplay?subjectid=300053850