Conservation Portfolio Home

Overall image of the Winterthur paintings studio. The dummy board is supported against foam board covered in glassine screwed to a temporary wooden frame. Treatment progress can be continually assessed with the dummy board, upright, in his intended viewing orientation.

Composite photomicrographs at 250X of a cross section taken from the blue robe. The inset image was taken under UV illumination with a Leitz Witzlar Aristoplan epi-fluorescence steromicroscope Comet EKE equipped with a Nikon camera. Seven distinct layers are present on this sample, which is a representative stratigraphy of the original painted surface.

 There are three coatings present on the surface. One of the coating layers is extremely thick. Severe discoloration of the surface is evident in the before treatment documentation. The majority of this treatment focused on the reduction/removal of degraded and discolored varnish.

Detail of proper left hand identified as an initial test area for varnish reduction. The wrist area illustrates an early test with diacetone alcohol solvent gel suggested by Richard Wolbers. The chalk rectangle helped document the test area. 

A cross section taken from the initial cleaned wrist suggested that diacetone alcohol was too aggressive. Methodological testing of neat solvents, solvent gels, and aqueous systems was carried out.

After choosing the cleaning system, it was tested in discreet areas of other colors to make sure it was safe to use overall.

Detail of tests in blue, red, and yellow areas.

 

Here I am working on the dummy board in the Winterthur paintings studio. 

 

The solvent gel was applied with a soft brush and moved around gently on the surface. It was then picked up with a dry cotton swab followed by clearance with the OMS: isopropanol mixture described earlier. Above you can see some of the gel removed with discolored varnish.

 

Detail of loaded gel removed from surface.

 

Working on the dummy board.

 

Detail of the figure's clothing during cleaning/varnish reduction. The area on the right reveals a blue surface with white stylized flowers and ribbons. The rest of the costume appears dark green due to heavily discolored coatings. 

Detail of previous image highlighting an area of old retouching (left) that is green to match surface with yellowed varnish rather than the original blue presentation surface.

 

Here I am cleaning and removing discolored solvent gel from the surface. 

During treatment shot with small area around proper left hand cleaned. Notice how much more three-dimensional the hand appears.

 

I needed to stand on a step-ladder to reach the figure's shoulders and head. 

 

During treatment, partially cleaned

Detail of area around proper left hand after cleaning

Detail of same area under UV illumination (handheld lamp). Note there is still a faint fluorescence even in the area that has been cleaned. This is sometimes referred to as a "skin" of varnish. It indicates that the painted surface has not been disturbed, which was one of the goals of using a gel-based system.

 

Detail of proper right side of pants, partially cleaned.

 

Detail of same area under UV illumination (handheld lamp)

Detail of area around old paper label under UV illumination (handheld lamp) after partial cleaning. The various fluorescent colors demonstrate the mixture and layering of coatings on the surface. My Technical Study of this dummy board further explores the varnish compositions using instrumental analysis.

 

Detail of lower portion of the dummy board under UV illumination (Broncolor lights) after partial cleaning.

 

Overall recto before treatment

Overall recto during treatment, partially cleaned

Overall recto, after varnish reduction/cleaning

After removing discolored and degraded coatings a new protective varnish with better aging characteristics is typically applied. For this project B-72 was chosen for its excellent stability and ability to achieve a matte surface. Here I am testing different concentrations of the varnish in a small area. The chosen concentration was brush applied when the dummy board was propped up vertically. 

After removing mismatched retouching, some distracting losses in the painted surface remained. Here are scrap pieces of wood that I intentionally marred in order to compare different fill materials. I spent additional time researching fill materials because the dummy board was going to be displayed in a semi-controlled interior space. I was concerned about the expansion and contraction of the wooden substrate and did not want to choose too rigid of a fill material that might contribute to new cracks in the wood. In the end I chose to make a custom hide glue and kaolin (clay) putty tinted with dry pigments, which is a traditional choice for panel paintings.

Detail of the proper lower left corner before treatment. 

Detail of proper lower left corner during treatment after filling thin vertical losses with hide glue putty. 

Detail of proper lower left corner after inpainting. 

Overall image after filling losses

The loss at the tip of the proper right hand had been filled in the past but the fill material was weak and crumbled during cleaning. The remainder of this old fill was removed and Araldite AV 1253 was chosen as the new fill material for this area. 

Here is the fill after applying the Araldite, a two-part epoxy with iron oxide fillers. Araldite is commonly used for loss compensation in furniture conservation because it can be carved after setting. Araldite is a much stronger fill material, but this loss extended to the edge of the dummy board so structural stability was important in this area. 

The area was intentionally overfilled because it could be carved and smoothed after setting. 

Here is the same fill after shaping. 

Here is the same area of loss after inpainting. 

This is a detail of inpainting on the dummy board. I used a modified tratteggio technique which utilizes thin juxtaposed and sometimes overlapping lines of various colors to achieve the final color. I liked this method of application for the dummy board because it also helped imitate the pronounced wood grain so that my areas of retouching were not overly flat and smooth.