undergraving

Undergraving is a term used in crafts and conservation to describe a technique in which a design, inscription, or texture is incised into a substrate beneath the object’s outermost surface. The mark lies below the finished face, becoming visible when the top layer is altered, worn away, or selectively removed. The concept is distinct from traditional surface engraving or from underglaze and inlay methods, and its usage is not as standardized as those practices.

Practitioners may create undergravings by engraving into an underlying core before applying a veneer, glaze, or finish, or by inserting a contrasting layer into a recessed channel beneath the top surface and then sealing it. In other cases, a top layer is applied over an engraved substrate and designed to wear away at predictable rates to reveal the motif over time. Advances in micromachining and laser techniques have expanded possibilities for controlling depth and visibility in undergraved motifs.

Undergraving appears in contemporary sculpture, jewelry, and architecture projects where hidden messages or textures are desirable. It is also discussed in conservation as a way to document historical inscriptions on fragile layers without exposing them to surface handling. The approach can enhance security features for objects by creating inscriptions that are difficult to detect without controlled surface alteration.

Because undergraving is less common than surface engraving, terminology and standards vary by discipline. Preservation concerns include ensuring the longevity of the concealed mark under different finishes and environmental conditions.