Stomacher and collar (probably Italian), ca. 1730.
From the Philadelphia Museum of Art.

Stomacher and collar (probably Italian), ca. 1730.

From the Philadelphia Museum of Art.

Stomacher, ca. 1700-1720.
From the Manchester City Gallery.
A stomacher was a triangular piece worn over stays or a corset.  Sometimes a stomacher was boned like a corset, often (as seen here) it was merely decorative.

Stomacher, ca. 1700-1720.

From the Manchester City Gallery.

A stomacher was a triangular piece worn over stays or a corset.  Sometimes a stomacher was boned like a corset, often (as seen here) it was merely decorative.

Corset, stays, and stomacher, ca. 1620-1640.
From the Manchester City Gallery.

Corset, stays, and stomacher, ca. 1620-1640.

From the Manchester City Gallery.