Patination isn’t Superficial
Patination isn’t Superficial
By Lark E. Mason, Jr.
Metal corrodes, the bible admonishes:
“Your gold and silver have corroded, and their corrosion will be evidence against you and will eat your flesh like fire. You have laid up treasure in the last days.” (James 5:3).
James is right. Though gold does not corrode, nestled against other materials it can become covered with corrosion, and ‘laying up of treasure’ is usually the cause.
Burying metal objects induces corrosion. Whether to preserve, hide, or to accompany the deceased into the afterlife, burial soil against metal causes corrosion. Our ancestors discovered acidic change on metal and used this or other materials to create a uniform appearance over the heat blackened or irregular colored metal surface.
Understanding corrosion, purposeful or not, is integral to understanding ancient and modern metal objects. Chemical processes are reactive or protective. Understanding the effects and why and how these occurred is difficult. Is an ancient Chinese bronze vessel patinated from burial or is it a later applied surface, disguising a repair? And if later, when? Was a Roman bronze figure recently patinated or was the surface manipulated during the eighteenth century, and if in the eighteenth century, was this protective, or was it the personal taste of a particular collector? Is a Tiffany bronze lamp base authentic or not?
It starts with metal; raw material, excavated, sorted, refined, and worked. Metal is used to make objects. Ancient Chinese bronze vessels are exemplars of this process, explained by Bob Mowry.
Once the metal object was made, it was patinated. The Metal Conservation Summer Institute publication, 'An introduction to the history of metals conservation' is a chronology of the earliest ancient examples of metal patination through the present, with discussions about techniques and materials. It shows experimentation and improvement.
Ancient Greek and Roman bronze patinated surfaces vary as do Renaissance bronzes discussed in The 2010 Metropolitan Museum Journal article, ‘Organic Patinas on Small Bronzes of the Italian Renaissance’
The Met established metallurgical laboratories in 1925, in concert with Columbia University Professor Charles Fink, author of a manual on the ‘conservation of bronze antiquities.’ The Met’s workshop was modeled on that of The British Museum, led by Harold Plenderleith.
Patination does not end with the ancient world, Tiffany patinated metal surfaces, using various techniques as did other metallurgists. Gilding, silvering, and other surfaces used today have ancient origins.
NY Times: 'ANTIQUES; Ancient Chinese Alchemy: Turning Bronze Into Art'
The caveat, ‘don’t clean it’ and ‘it would have been worth so much more had it not been cleaned’ is covered in The V & A guide to cleaning metal. V& A Museum: 'Cleaning metals: basic guidelines'
Seeing first-hand, looking at ‘surfaces’ in addition to the ‘object’ is foundational to understanding metal works of art. ‘Looking’ at surfaces can be done in most museums and in New York City, The Metropolitan Museum is a great resource. Plan which displays to view, observe, and take notes or photographs. Attend the exhibits of the Winter Antiques Show, auctions at Sotheby’s, Christie’s, or Bonhams, or galleries during Asia Week New York, where gilded or ancient bronzes can be seen at Carlton Rochell Asian Art or J.J. Lally, and other dealers and works of Louis Comfort Tiffany. New York City offers unparalleled access to see patinated surfaces on astounding works of art, with experts who share their passion for the subject.
