Attics and Basements and Closets, Oh My! Part 19: Gilded Frames

​While those of us in the conservation department grapple with the many challenges facing our society, we are finding comfort in our family heirlooms and treasures—many of which require our attention. We understand that like us, many of you may be turning to your family treasures for comfort during these trying times. Thus, the conservation department would like to share tips on ways to care for your personal collections and assure you that we are here to support you and the collections that you hold dear. 

Each week a different student from the Winterthur/University of Delaware Program in Art Conservation will address ways to care for the collections in your cupboards. This week’s post focuses on caring for gilded frames and was written by rising third-year Wooden Artifacts Fellow, Jonathan Stevens.

Frames 

Frames can serve as a practical means of protection and display for pictures, mirrors, textiles, and many other objects, but they can also have artistic or historical value in their own right and can powerfully alter the way an artifact looks. Frames can be artist-made and can represent the original intent of an artist or maker. They can reflect an object’s historical context or its history of ownership and exhibition, and they can even be an integral part of an artwork itself. Historic frames can also bear labels, inscriptions, maker’s stamps, and other material evidence of an object’s history or authenticity.

​Even the plainest or simplest frames can lend significant artistic, historical, informational, and market value to the objects they surround. While framing is often considered a matter of personal taste, it is important not to discard an original or historic frame needlessly. Dissociation is one of the most common agents of deterioration that affects frames. If you do decide to reframe a piece, it’s a good idea to retain and carefully document the original framing materials, especially if you are in doubt of your frame’s history or provenance. While most damage to historic frames can be remedied or compensated for with conservation treatment, missing frames that have not been documented can be difficult to replace.

Materials 

While frames can be made using a wide variety of materials and processes, this post will primarily discuss gilded wood picture frames. Please consult our other Caring for Family Treasures posts or contact a conservator for information about treatment and care of frames made from other materials. 

Gilding is a process that gives objects a golden appearance through a thin application of gold or other metals, and it can be applied to a variety of substrates using a variety of techniques and processes. Wooden picture frames are usually gilded with gold leaf—thin sheets of gold that have been hammered to a thickness that can be measured in tenths of microns or thousands of gold atoms (at least for most modern products; pre-industrial gold leaf was beaten entirely by hand and was thicker than most leaf produced today). 

Gold leaf is most commonly adhered to wooden objects using one of two traditional processes: oil gilding, which uses a drying oil as a mordant; or water gilding, which uses a water-soluble animal protein glue as an adhesive. Water gilding involves a labor-intensive surface preparation with multiple coats of “gesso” (chalk or gypsum in animal protein glue that is often carved to add detail to the finished product) and “bole” (a finely ground colored clay that allows the gold to be burnished to achieve a smooth, shiny surface). These two processes are also sometimes used on different elements of the same frame.

Gilded frames also often incorporate applied ornament made from composition, or “compo,” a material used since the late eighteenth century to replicate detailed designs more quickly and with less skill than is required with traditional woodcarving. Compo is made by heating animal protein glue, linseed oil, chalk, and natural resins to form a dough-like material which is then pressed into rigid molds.

​Gilded surfaces may be finished with a translucent toning layer, such as dilute animal protein glue or shellac, which can serve to protect the delicate gilding or modulate the appearance of the surface. Silver leaf, for example, is sometimes toned with yellow resins or shellac to resemble gold leaf. Some surface coatings on gilding can be difficult to discern with the naked eye. They can also be fragile or easily soluble, making them vulnerable to damage from inappropriate cleaning or handling.

Environment and Display 

Like paintings and furniture, gilded wood frames are sensitive to changes of temperature and relative humidity (RH). Extremes of RH can cause dimensional change and distortion in wood, leading to disruption or loss of ground layers, gilding, and composition ornament. High RH can also cause condensation on delicate gilded surfaces and can lead to mold growth and attack by wood-boring insects. Frames and pictures hung on damp or cold exterior walls can be especially prone to problems caused by incorrect RH. 

Temperatures around 70º F and RH near 50% are ideal, but if maintaining these conditions is not possible, avoiding drastic or rapid changes in temperature and RH will still help greatly in preventing deterioration. Airborne pollutants like soot, dust, cigarette smoke, or cooking grease can also damage gilded surfaces or complicate cleaning, and frames can be vulnerable to breakage or losses resulting from improper handling or insufficient hanging hardware. 

Keep frames in a clean environment and avoid excessive handling. When moving a frame, use two hands to grasp the frame on both sides, making sure not to lift by fragile carvings or ornament. For hanging hardware, avoid threaded screw eyes, especially for heavy pictures or frames, as they can easily loosen over time. D-rings screwed to the back of the frame are a more reliable way to attach picture wire, and wooden or metal French cleat systems are another reliable hanging option.

​Cleaning and Care 

Gilded surfaces can be extremely delicate, and their cleaning presents special challenges. Dust can obscure the appearance of a gilded frame and can attract moisture to the surface, leading to further deterioration. 

Frames can be gently dusted using a soft natural bristle brush. Feather dusters should be avoided, and frame conservators often recommend sable or squirrel-hair brushes or a never-used soft cosmetic brush. Any more involved cleaning of historic gilded surfaces should be done by a conservator. Wiping with a dry cloth can cause dust particles to abrade the surface of the gold leaf, and it can disturb fragile elements and flaking gilding. Cleaning with commercial cleaning solutions, solvents, or even water can permanently remove gilding and should be avoided at all costs. If cleaning a mirror or glass in a gilded frame, use an ammonia-free glass cleaner and never spray glass cleaner directly onto the glass surface; this often causes liquid to drip down and pool against the frame’s inner edge where it can seep into the frame, damaging the frame, the mat liner, or the artwork that the frame is meant to protect.  

If bits of gilding, composition ornament, or carving become detached from your frame, save them in small separate plastic bags (so they don’t further abrade each other), and, if possible, make a note of their original locations. Saving these small pieces preserves the original fabric of the frame and can often make subsequent conservation treatment easier, faster, and less expensive than if elements have to be replicated from scratch.

​Although it may be tempting to use a gold-colored paint to touch up a worn frame, this is not advisable. “Gold” paints are often actually pigmented with copper alloys like brass or bronze, and while they might match the gold of the frame initially, they almost always oxidize to an unappealing brownish-green layer that can be very difficult or impossible to remove. In the best cases these paints can be removed with harsh, toxic chemicals, and in the worst cases they become inextricably linked to the original gilding layers below, necessitating more invasive treatment options or removal of original material. When in doubt, it is always better to accept a small amount of natural wear—which is, in fact, often prized on historic frames—than to introduce harmful cleaners, paints, or other substances to a gilded surface.   

Frames can be far more than accessories; they can bring meaning and significance to the objects they house. Keeping in mind their environmental needs and avoiding some common pitfalls of care and handling are essential. A good understanding of preventive conservation principles can go a long way toward preserving the integrity of your own treasured frames. 

Additional Resources 

The Frame Blog takes an in-depth look at the history, meaning, and preservation of frames. Blog editor Lynn Roberts’s books are also indispensable resources on European picture frames.  

A demonstration of water gilding technique from the Victoria and Albert Museum 

Information about framing paintings from the Canadian Conservation Institute

Information about matting and framing works on paper from the American Institute for Conservation’s Book and Paper Specialty Group

We hope you are enjoying these entries in our series focused on caring for your family heirlooms. This series will continue throughout the summer and cover a variety of items and materials. If you have any comments on the series thus far, including materials you’d like to see covered in future posts, please email us at art-conservation@udel.edu. The previous posts in this series are available on the Department of Art Conservation website here.

You are in our hearts and minds as collectively we face many challenges. We hope you and your loved ones are safe and healthy. When we emerge from this global crisis we must and will rely on art and culture, preserved for today and for future generations, to foster joy, well-being and hope. We encourage you to visit our web site for regular updates on our department of art conservation and news coverage of our treasured students and alumni at home and abroad.