Author: Jessica Ford

45th Annual Meeting – Paintings Session, June 1, 2017 – “Using Butvar® B-98 as a Consolidant for Friable Matte Paint by Claire Winfield”

Covering a pair of practical case studies, Claire Winfield’s presentation on her recent uses of Butvar® B-98 was clear and informative. Winfield, the Associate Painting Conservator at Saint Louis Art Museum (SLAM), featured two artworks that share the characteristic of having friable matte paint, but the process and purpose for consolidation of each one varied. Her ability to modify her approach for each situation was guided by research and first-hand tests with Butvar® B-98.

Molecular structure of Butvar®. Image taken during presentation.

Butvar® B-98 is one of a series of trademarked polyvinyl butyral resins, which are valued for their clarity, adhesion to varied surfaces, rheology, toughness, flexibility, and aging characteristics. Butvars® are available in a range of molecular weights (MW) and can be applied in a variety of solvents by brush or spray. They are typically used in objects conservation for materials such as deteriorated wood, stone, plaster, bone, fossils, and baskets, because they can retain a matte surface and cause little color saturation.

In both of Winfield’s featured treatments, she needed to stabilize paint without altering its optical properties – a steep challenge given their powdery surfaces. Winfield focused on the energy relationships between Butvar® B-98 and the painted surfaces, reducing the adhesive’s particle size (B-98 is the lowest MW Butvar® available) and spray applying it in multiple dilute coatings to promote penetration. Keeping the spray tip completely clean and pre-wetting the surface with solvent were helpful in this process.

Historic information about Fabspray. Image taken during presentation.

The first case study was Enforcer (1962) by Larry Poons, composed of Liquitex acrylic paint and Fabspray on canvas. The Fabspray, a spray paint for fabric with vinyl and alkyd resin binders, unfortunately aged very poorly, having deteriorated to the point of actively shedding pigment. The goal of treatment was to keep the paint in place for safe dusting of the surface. Adhesive tests included Butvars® of varying weight, gelatin, and methylcellulose. Due to its small particle size, low viscosity in ethanol, strength, and minimal visual effect, a 1% Butvar® B-98 in ethanol was chosen as the consolidant. Since the Liquitex and Fabspray were applied to the painting in discrete areas, it was possible to mask the Liquitex areas while spray applying six coats of dilute consolidant to the Fabspray. The results were successful in that the paint no longer actively sheds and remains visually matte; however, the surface still cannot be safely dusted, and there was a slight but acceptable saturation of the color.

Photomicrograph of problematic paint. Siegfried Reinhardt, Micenic, 1942, oil, Siegfried Reinhardt. Image taken during presentation.

Micenic (c. 1942) by Siegfried Reinhardt, an oil painting on pressed board, was the second case study. The paint layer was locally cracked and lifting away from the board, and it was also lacking in cohesive strength: the lifting paint crumbled from brush contact and could not withstand heat. Following tests, the surface was pre-wet with 60:40 toluene:ethanol then then sprayed overall with 2% Butvar® B-98 in the same solvent mix to give the paint cohesive strength. Ethanol helped lower the viscosity of the adhesive, and toluene prevented tidelines caused by the paint’s slight ethanol sensitivity. BEVA® 371 in naphtha with heat assistance could then be applied to readhere the lifting paint to the board without undermining the cohesion provided by the B-98. This two-layer consolidation process successfully preserved both the structure and appearance of this painting.

Winfield’s work provided two responsible and creative examples for how Butvar® B-98 can be a useful addition to a paintings conservator’s toolkit.

45th Annual Meeting – Paintings Session, June 1, 2017 – “Conserving the Paintings of Romaine Brooks by Tiarna M. Doherty”

On the final day of specialty group presentations at AIC’s Chicago meeting, Tiarna Doherty, Chief of Conservation at the Lunder Conservation Center, Smithsonian American Art Museum (SAAM), rewarded attendees with a lovely presentation about the singular artist Romaine Brooks. The Smithsonian Renwick Gallery mounted the exhibition “The Art of Romaine Brooks” in 2016, and Doherty examined over 30 paintings by Brooks in preparation, many of which were featured in the show. Weaving into a captivating story Brooks’s biography, aesthetic preferences, and technical practices, Doherty also conveyed the rationale for her practical conservation approach in response to how the paintings have altered over time.

Still image from presentation. Painting show in detail (left), overall normal light (center), and ultraviolet illumination (right). Romaine Brooks, Una, Lady Troubridge, 1924, oil, Smithsonian American Art Museum, Gift of the artist, 1966.49.6.

Romaine Brooks (1874-1970) is known for her stunning portraits, often featuring friends who were leading figures in the arts and humanities at the time. Born in Italy but raised in New York, Brooks’s father left when she was young, and her mother was not supportive of Brooks’s artistic pursuits. From 1890-1900, she lived in Capri with many other ex-patriots with non-traditional lifestyles; the location was a refuge following Oscar Wilde’s 1895 trials in London. Brooks met her husband in Capri, but their marriage was unsuccessful in no small part because he disapproved of her preference for masculine attire. She eventually settled in Paris in 1905. Her unpublished autobiography, which she illustrated with drawings, was titled “No Pleasant Memories.”

Brooks recorded very little about her aesthetic preferences or artistic technique, leaving only her artistic output and a few historic photographs to fill in the blanks. Her painting technique reveals some academic knowledge, though she may not have had formal training. Chalk lines and colored ground layers, such as the salmon orange preparatory layer in The Charwoman (1904), were followed by thin washes of paint and numerous glazes composed of her own mixture of oil and resin. She often used oil paint to reinforce contours on top of natural resin varnish layers to create the final surface. Painted black dashes, and in one case silver dashes, define the outer boundaries of many paintings.

In addition to painting and drawing, Brooks demonstrated an innovative attentiveness to interior design. Frame design and surface finish were clearly a consideration in her pursuit of Whistler-influenced harmony of color and tone. In one example from Doherty’s presentation, Brooks had a particular frame with a large rabbet in mind when planning a painting’s composition, as she painted the canvas only where it would show within the frame window. In another example, both the painting and the frame had a black ground layer visible beneath the finished surface – such efforts earned the accolades of “reigning in harmony” in a 1910 exhibition review.

Not surprisingly, the natural resin-containing layers of Brooks’s paintings have darkened over time. Brooks herself may even have seen the changes begin, as she chose to keep most of her paintings until her death. The presence of glazes and varnish in alternating layers with original oil paint make conservation especially challenging. In addition, conservators at SAAM observed that later applications of Paraloid® B-72, now getting cloudy, were difficult to remove safely due to sensitivity of the original materials beneath. Treatment goals leading up to the Smithsonian’s exhibition were therefore a combination minimal intervention and passive technology. When possible, degraded varnishes were reduced and surfaces resaturated. To restore some of the original cooler tonality, gallery lighting was employed to virtually compensate for some of the current altered appearance.

Doherty reminded us of Oscar Wilde’s relevant words from The Portrait of Dorian Gray, that “some things are more precious because they don’t last long.” But a conservator does what she can. This careful study of an artist and her technique led to both a thoughtful approach for displaying Brooks’s paintings, aged but still striking; as well as this transmission of her harmonious original vision.

43rd Annual Meeting – Paintings Session, May 15, "Rediscovering Renoir: Materials and technique in the paintings of Pierre-Auguste Renoir at the Art Institute of Chicago" by Kelly Keegan

Renoir is one of those art historical giants that I’m sometimes guilty of overlooking, simply because of how frequently his imagery appears in contemporary culture. An upcoming treatment of a Renoir painting at work, though, meant that it was high time to take a closer look. Fortunately, Kelly Keegan of the Art Institute of Chicago gave a fantastic presentation on “Rediscovering Renoir” at the 2015 AIC conference, which was brimming with details about the artist’s materials and techniques, and beautiful photomicrographs and graphics.
The presentation was a summary of findings from the in-depth technical study of Renoir’s 15 paintings at the Art Institute of Chicago, conducted as part of the Online Scholarly Catalog Initiative. Examination techniques included x-radiography; infrared, transmitted light, and ultraviolet imaging; x-ray fluorescence spectroscopy; scanning electron microscopy/energy dispersive x-ray spectroscopy; polarized light microscopy, surface-enhanced Raman spectroscopy; thread counting; and, of course, lots and lots of looking under the microscope.
Renoir was both less and more methodical than I expected. For example of the former, he didn’t have a reliable art supply merchant. His canvases ranged in fineness, and thread counting demonstrated that they never came from the same bolt of cloth. Although most of the paintings are now lined and on non-original stretchers, seven canvas stamps from four different suppliers were found. His ground layers were usually white or off-white, with dragged inclusions and palette knife marks indicating application by the artist. The use of the palette knife often exposed the tops of the canvas weave.
Renoir’s compositional planning shows his meticulous side. Even the highly impressionistic work Chrysanthemums includes a graphite underdrawing with individual petals. The artist varied his preparatory drawing medium, using dry media, blue or brown paint, or red lake washes. Slight adjustments were common, and a dramatic change was discovered in Lunch at the Restaurant Fournaise, the catalog cover image: an isolated two-person encounter was initially depicted, but the final product has three figures. Later in Renoir’s career, infrared examination shows the debilitating effect that rheumatoid arthritis had on his once-confident draftsman’s hand.

Graphic illustrating Renoir's use of yellows in 15 paintings. (Photo credit Amber Kerr.)
Graphic illustrating Renoir’s use of yellows in 15 paintings. (Photo credit Amber Kerr.)

Renoir’s color palette included vivid pigments, including emerald green, cobalt blue, various bright yellows (see image above), vermilion, and red lakes, in addition to iron oxides. One color he considered an “unnecessary purchase” was yellow ochre, which he ironically preferred to mix himself using much more expensive pigments. Although he did a lot of blending on the painting, he kept his brush clean to prevent muddying of the colors. In contrast to most other Impressionists, Renoir’s paint layers are quite thin relative to the ground layer. The influence of his teenage training as a porcelain painter is evident in his use of thin glazes, especially with luminescent red lakes over white ground. He used a palette knife at times to scrape away layers and create texture in the interstices of the canvas weave.
This presentation was chock full of technical information and interesting quirks about Renoir that not only make me feel more prepared to approach a Renoir treatment, but also give me a much better appreciation for an artist that deserves a close look. His work shines under the microscope and when considering the individual behind the paintings. The Online Scholarly Catalogs are a wonderful resource, and I’m grateful to have gotten Keegan’s dynamic overview of the Renoir content.