The Science of Art Conservation Read More
Art conservator Batyah Shtrum discusses her restoration work for the Jewish Museum’s collection.
In early 2018, the Jewish Museum opened Scenes from the Collection, an exhibition that re-imagined the presentation of the collection through nearly 600 works from antiquities to contemporary art — many of which were selected for public display for the first time.
In preparation, the Museum undertook the conservation of hundreds of objects in the collection. This meticulous care-taking allows the artworks to remain in good condition, and be enjoyed for generations to come.
To unpack the complexities of conservation, a true combination of art and science, the Museum spoke to Batyah Shtrum, a partner in SBE Conservation. Along with her colleagues Sarah Barack and Beth Edelstein, the trio have worked on the conservation of objects in the Jewish Museum collection since 2008. Ten years later, Shtrum gave us a peek behind the curtain to see how they weave their magic, bringing art and objects back to life.
How do you describe art conservation to those unfamiliar with it?
Art conservation is the care and protection of cultural property. As conservators, our main goal is to focus on what’s best for a particular object. This means understanding the piece to the best of our abilities and choosing the appropriate conservation materials, such as adhesives and solvents, to carry out the physical work.
This includes — but isn’t limited to — hands-on work for the actual repair of damaged objects. Other aspects of our job include collection and materials examination, environmental monitoring of temperature and relative humidity, rehousing of collections, materials and fabrication, and education to disseminate knowledge to stakeholders, such as collection managers and curators.
Per the code of ethics of the American Institute of Conservation of Historic and Artistic Works, we use reversible materials in the conservation of an object. A variety of reasons might necessitate the removal of a historic restoration materials over time, including danger to the object itself, failure of the material, or aesthetic appearance, for example if became discolored with age. This is why conservators prioritize the use of reversible materials with good aging properties.
How do you assess an object you are conserving?
The first step in conservation is understanding what the object you are entrusted with actually is. This means knowledge of what material or materials it is composed of, and how it was fabricated or manufactured. Close examination of a piece, often with the aid of a head loop, microscope — or even ultraviolet light — can help with a more in-depth understanding of a piece. For example, UV light can show old restorations on a painting or ceramic. There are also more advanced analytical procedures available. Information related to who made the piece, where and when it was made and — when possible — its history, are all important aspects for a comprehensive understanding of an object that should be established before any conservation treatment begins.
Take us through the steps of how you restored the silver Torah case with finials currently on view in Scenes from the Collection.
Through examination and analysis of the Torah case, we were able to understand the object more fully and choose the appropriate cleaning methods to attain the safest and best outcome. We spent almost 100 hours working restoring this object.
When the Torah case was first examined, it was assumed that it was silver, as the surfaces exhibited an even silver sulfide tarnish layer overall. My colleague Sarah Barak test cleaned a small area using a non-vinyl, soft eraser. Before we begin, conservators always carry out small tests on objects to ensure the chosen method will work as planned.
Sarah was surprised to see that some of the raised areas of decoration appeared to be gilded. We brought in Senior Curator Susan Braunstein to discuss our findings.
Polishing metals removes material. In most cases with gilded metals, the gilding layer is extremely thin, so polishing can remove it all together, changing the visual appearance of the piece permanently.
In order to confirm the presence of gilding, we brought in a company who performed X-ray Fluorescence, or XRF, a non-destructive analytical technique used to detect the elemental composition of an object. The analysis confirmed the presence of gold both on the surface of the piece as well as on the eraser crumbs, meaning we had removed a small amount of original gilding with the mechanical action of the eraser. At this point we realized we had to change our treatment approach on areas that incorporated gilding. Fortunately, the test area allowed us to understand where gilding was present, which meant we could safely continue using the eraser on areas that were not gilded.
We began testing electrolytic reduction, which incorporates a non-abrasive cleaning method. The object became tarnished as corrosion passed through micropores in the thin gilding layer. In the course of the cleaning process, silver that had become a part of corrosion products is reduced back to metal, which emerges as granules or a layer weakly attached to the main material. The silver object itself is the cathode and in our case, a stainless steel pin was used as the anode. We used sodium bicarbonate — baking soda — as the electrolyte, followed by a dilute solution of formic acid to further remove loosened tarnish. This method worked extremely well, so we moved forward. We had to be sure not to wet the surface too much since we did not want liquid to seep between the metal plates and into the case that still contained the parchment Torah scroll. The before and after images of this object are quite striking. We were quite pleased with the outcome.
Any other surprises on objects you worked on for the Museum?
Beside the fact that the Torah case was partially gilded, a big surprise involved a pair of Torah staves.
Upon examination of the staves, I came across candle wax residue on the surfaces that indicates they must have been used as candlesticks. Often with ceremonial objects, leaving remnants of their use is desirable as an historic record. When I informed the curator of my finding, she was very surprised as it seems these Torah staves may have been purposefully desecrated. After discussion it was decided that the wax should be left intact as evidence of the object’s history.
What’s the greatest feeling of accomplishment you derive from your work?
As a conservator I feel honored, and admittedly sometimes intimidated, to be entrusted with the care of an artwork. The true satisfaction and feeling of accomplishment comes when a damaged work, that looks so different than it had when it was made, comes back to life, and can once again be appreciated as intended.
See many of these works on view now in Scenes from the Collection.