The Old Newbury Crafters (ONC) 225 mark is found on sterling silver pieces handmade by Old Newbury Crafters, a Massachusetts-based silversmithing firm known for its traditional, handwrought techniques. The mark typically includes the ONC initials and the number “225,” which serves as a pattern or item reference within their catalog. This number helps identify the specific form, design, or size of the piece, which may range from flatware to hollowware. ONC pieces are prized for their craftsmanship and historical continuity, having produced silver entirely by hand since the early 20th century. The 225 mark plays a vital role in cataloging and verifying authenticity for collectors and silver experts.