Author: SGowler

Francisco Trujillo’s talk was an excellent addition to the overall conference theme of ethical considerations and critical thinking as it highlighted the impact a conservator’s assumptions and biases can have on the course of analysis and treatment. He described the treatment of a Dutch illuminated manuscript, The Hours of Catherine of Cleves, in preparation for exhibition at The Morgan Library and Museum.  The Book of Hours contains over 150 illuminated miniatures designed and painted by an artist known as the Master of Catherine of Cleves. The manuscript was originally bound as one volume, but was later split into two volumes and reordered. Treatment of the manuscript involved disbinding, consolidating the media on each page (with 1-2.5% isinglass in water and ethanol), and rebinding the folios in their original order.

As treatment progressed, Trujillo began noticing the presence of a non-copper based “smooth blue” pigment, possibly ultramarine. The “smooth blue” was found on pages that would have been facing each other in the original manuscript (before it was split and reordered) and was not found on surrounding pages. FCIR and XRF  analysis revealed that ultramarine was present in these “smooth blue” areas along with azurite. Trujillo began to wonder if the Master had selectively used ultramarine on a handful of leaves, possibly mixing it with azurite, or if the ultramarine had been painted on top of the azurite, a later “sleight of hand”? Since at this point Trujillo had no other evidence that the Master ever used ultramarine, he assumed that the presence of ultramarine was a result of 19th century “touching up” when the manuscript was split into two volumes.

Trujillo pursued the “sleight of hand” line of inquiry, but then came across evidence that perhaps the Master of Cleves had, in fact, used ultramarine as an aesthetic choice. This led him to once again question his beliefs about the Master’s working methods; though there was evidence that many of the leaves had been “doctored” when the manuscript was split, there was also evidence that the blue pigments were mixed, quite possibly by the Master. He also found cobalt mixed into to some of the blues, and now leans toward the belief that it was the Master himself who used ultramarine on a select number of folios.

Trujillo did a nice job of calling attention to the assumptions conservators make about the objects they’re working on and the impact this can have on treatment decisions. He acknowledged that pursuing the “sleight of hand” theory – while fascinating – diverted his attention for a while and kept him from seeing other important evidence in the manuscript.

In preparation for a 2012 exhibition of Charles M. Russell’s watercolor paintings, Jodie Utter, Conservator of Works on Paper at the Amon Carter Museum of American Art , undertook an investigation of the artist’s techniques and materials. I really enjoyed this presentation; I knew nothing about Russell or his work prior to the talk and Utter was successful in sharing her excitement about the artist by putting together an interesting narrative of his life, process, and development as a painter.

Russell was born in St. Louis in 1864, and moved to Montana as a young man to work on a sheep ranch and then as a night wrangler on a cattle ranch.A self-taught artist who began drawing and painting in his spare time on the ranch, he began painting full-time in 1893. A turning point in Russell’s career was a trip to New York in 1903-04, where he met and was influenced by the work of other painters and shifted from working in transparent watercolor to opaque watercolor. He produced over 1400 watercolors in his lifetime

Utter visited Russell’s still-intact studio to take samples of his paints, which she analyzed using polarizing light microscopy and x-ray fluorescence; as a point of comparison, she also analyzed samples of contemporaneous paints from unopened tubes.  Materials found in his studio reveal that Russell used the highest quality brushes, paints, and papers available to artists in the American West in the mid-19th century. He used red sable brushes, the handles of which he cut and whittled to points in order to shape paint layers (he also chewed on his brushes, as evidenced by all the teeth marks!). The most common paint found in Russell’s studio was Chinese White watercolor, introduced in 1834 as the first reliable opaque white. Utter also found many paint tubes in Russell’s studio; she highlighted how revolutionary paint tubes were for artists at that time (introduced in 1840), allowing them to purchase high quality paints in large quantities. Also, since tube paints have more body than pan paints, they could achieve different results.

Infrared examination of Russell’s paintings revealed that the underdrawings of his earliest paintings were “overdrawn” – he was drawing figures over and over again, including lots of details, trying to “get things right,” without erasing much. Later underdrawings were much more minimalist – confident sketches with little detail. His color palette evolved from very basic to more developed – in a 1897 painting, there were 17 different colors of transparent watercolor in use –  to a sophisticated use of complementary colors. Russell was introduced to color theory during his visit to New York; afterwards, he began using less black in the dark areas of his paintings – shadows were created with combinations of blues and greys. Russell used traditional watercolor techniques, like layered washes and  scrapping away paint layers to achieve highlights, but he incorporated many unconventional techniques as well. Russell was also an oil painter and a sculptor and he adapted techniques  – most notably, impasto – for his watercolor paintings.

Due to their stability, reversibility, and working properties, Lascaux 360HV and 498HV adhesives are becoming increasingly popular in book and paper conservation. Samantha Sheesley of the  Conservation Center for Art and Historic Artifacts presented three case studies of treatment applications that take advantage these properties.

The first case study involved treatment of a set of “Sailor Jerry” drawings on transparent paper. Both the presence of water-sensitive media and the reactive nature of the transparent paper meant that Sheesley was looking for a way to mend the drawings without introducing moisture. Lascaux 498HV was brushed in an even film layer onto a sheet of silicone-coated polyester and then quickly dried with a hair drier. Sheesley pointed out that this quick drying is an important step in order to prevent dust from settling into still-tacky adhesive. After drying, a sheet of tengucho mending tissue was placed on top of the 498HV film layer; the adhesive was reactivated with an iron to adhere the paper to the film.  After removing the silicone-coated polyester, the adhesive-coated tengucho was used to create mending strips that were applied to the drawings with heat, resulting in nearly-invisible mends that are easily reversed with either heat or solvent (acetone or toluene).

The second treatment example of was the re-lining of a lithographic poster. A hydrophobic coating on the paper and water-sensitive media required a dry lining method. Lascaux 498HV was applied to a sheet of silicone-coated polyester (a light mist of water under the polyester secured it to the bench) and squeegeed in multiple directions to create a thin, even film – Sheesley emphasized again that it was important to work quickly when applying and drying the film layer in order to avoid dust settling in the adhesive. Lining paper was placed on top of the dry adhesive film and adhered with an iron. Once cooled, the silicone-coated polyester was pulled away from the lining paper. The poster was placed face down on a suction table to keep all pieces in place and then the lining paper was dropped adhesive side down, tacked in place with an iron, removed from suction table and ironed overall.

The third case study – in my opinion, the most ingenious of the applications –  involved the use of a Lascaux mixture as a fill material for a convex photo button with a severe horizontal split. The button was a silver gelatin print with a cellulose nitrate coating on a metal substrate. The tented split created a gap that was both structurally and aesthetically problematic. Sheesley needed a fill material that would be flexible enough to accommodate dimensional changes in the object. She mixed equal parts Lascaux 360HV and 498HV, in order to take advantage of the unique properties of each, and added pigment. As in the first two examples, this mixture was brushed onto silicone-coated polyester and quickly dried. She scored the edge of the pigmented film and removed a small strip which she then rolled into a coil –  the inclusion of Lascaux 360HV in the mixture, which retains it’s tackiness even when dry, meant that there was just enough residual tackiness for the adhesive film to stick to itself. After mending the photo with small strips of Beva (which were inserted in to the crack with very fine-point tweezers) the Lascaux coil was fitted into the gap and tacked in place with an iron. Sheesley then ironed the coil overall through a sheet of silicone film which imparted a shiny texture to the surface of the Lascaux fill, mimicking the surface quality of the cellulose nitrate for better visual integration. The fill was then inpainted with acrylics. The “after treatment” photos of the button were impressive – I hope an appropriate object comes across my bench soon so that I can try out this technique!

Q: Does creating repair tissue using dry adhesive rather than wet adhesive (i.e., brushing diluted Lascaux onto mending tissue) create a less transparent mend?
A: Sheesley tested both methods and found then to be similarly transparent. She also speculated that the the dry film methods would be more easily reversible, since the adhesive doesn’t penetrate into the mending paper fibers as it would in a wet application.

Q: Were any adverse effects of using the hot iron next to the cellulose nitrate?
A: No harmful effects were observed.

Q: Was there any residual tackiness on the coil infill, since it contained 360HV?
A: No, the presence of 498HV in the mixture and the acrylic paints on top of the fill meant that there was no remaining tackiness.

Q: Concerns about reversibility.
A: Sheesley stated that though reversing the treatments could be time consuming, she was able to reverse all of her repairs.

Tanya Uyeda, conservator at the Asian Conservation Studio at the Museum of Fine Arts, Boston, kicked off the first BPG session of the conference with an interesting and nicely illustrated talk on the treatment decision-making challenges presented by Japanese paintings. Executed on either silk or paper, Japanese paintings are mounted onto folding screens, sliding doors, and scrolls – inherently kinetic formats that pose many conservation challenges.

The preservation of these formats is dependent on periodic remounting of the paintings. The operating assumption for Japanese paintings is that they have been mounted and re-mounted many times before entering Western collections. In order to accommodate the kinetic nature of these paintings, treatments tend to be rather invasive, requiring careful evaluation of when and how to incorporate past repairs into a structurally, aesthetically, and ethically appropriate result. Japanese paintings have often been re-mounted onto different formats; one example Uyeda shared was a pair of paintings that had originally been mounted to sliding doors and were later mounted as scrolls to facilitate exhibition. A painting’s primary support can serve as a clue to it’s original format. In this example, the sliding door paintings were on quite heavy paper, which doesn’t lend itself as well to the scroll format and can lead to structural problems when the paintings are forced to move in new ways. The decision was made to return to these paintings to their original format. Uyeda was quick to point out that changing formats always has consequences; these remounted paintings will now require new storage space.

Problems with previous repairs include mismatched colors, repair materials that are too strong for the original silk, and weak brush strokes that can diminish the aesthetics of the piece. Since curators and clients are attached to what the paintings look like, care is taken to ensure that the new treatments receive ethical treatment that is also sympathetic to the aesthetics of the object. Past mounters would compensate for losses with patches of painting silk attached to the back of the object; this repair silk wears differently than the original silk, causing both structural and aesthetic problems. The MFA currently has a limited stock of painting silk from Japan they use for loss compensation; this silk has been irradiated, which deteriorates it enough to weaken the repair fibers and achieve a better color match. They also have a stock of mounting silk for remounting scrolls. The MFA strives to choose mounting silk that is complementary to the aesthetics and the time period of the original painting. If the current mounting is appropriate, complementary, and usable, they will leave it.

The current Japanese standard for treatment of paintings is that no non-original materials remain, but the MFA takes a different approach, particularly with regard to inpainting. The ethical standard the MFA follows is not to inpaint, but just to tone the areas of loss. However, previous treatments often exhibit extensive inpainting and there are instances when the decision is made to retain these repairs.  Uyeda discussed a few examples of paintings in which the previous inpainting was reused, since to remove it would leave an unacceptable void in the painting. Traditionally, toned paper was sometimes used as a lining in order to affect the final appearance of the paintings. Uyeda showed a lovely example of a painting that, based on evidence that it had originally been lined with blue paper to create a “night sky” effect, was relined with blue toned paper in order to retain the aesthetics.

I appreciated that Uyeda highlighted the fact that the only reason most of these paintings still exist is because they have been regularly remounted and acknowledged the expectation that they will be treated again in the future. Ethical considerations of past repairs was a thread that ran through many of the talks; Uyeda’s served as a good reminder that all of the work we do exists at one point on a continuum of past and future treatments.

Q: Do they include any of this narrative about past repairs and choices about remounting on the exhibit labels?
A: No, MFA practice is to only include tombstone information on labels.

Q: When remounting hanging scrolls, do they change/replace the roller knobs?
A: They occasionally reuse the knobs if they’re in good condition, but since original knobs are often ivory and many of these pieces go out on international loan, it has become the policy of the MFA to remove the knobs prior to loans in order to avoid the difficulty of transporting ivory through customs.