A Conservation Project
Signed ‘K’
Oil on canvas
610mm x 505mm
This portrait had been given to the owner by the artist after he split up with the subject and could no longer bear to be reminded of her. The name of the girl and the name of the artist have been forgotten. It is signed ‘K’ and dated 1976. At some point it was accidentally splattered with white paint, possibly an emulsion. For this reason the client came to me to ask me to undertake this conservation project. The reverse of the canvas was covered in animal hair and thick layers of dust. It appeared that it had been stored for a long time in a dry environment.
The painting is unframed and its wood strainer is in good condition. The strainer keys are missing.
Canvas
Oil on cotton duck, pre-primed canvas. The canvas is very thin, taut and nailed to the strainer – the nails are rusted.
Paint Layers
The paint surface is in reasonable condition, but there are small splash marks of white paint across the painting, possibly emulsion or wood paint. In the lower left corner there are faint scratches although these could be smears of the same splattered white paint.
Treatment Report
Surface Cleaning
When approaching this conservation project, I was concerned about exposing the paint and canvas to water so I used dry, soft sponges to give the painting an initial clean. This removed a significant amount of dust and grime on the front and reverse of the canvas.
A pH test on the surface of the painting returned a result of pH 7. This indicated that any aqueous cleaning solution used on the portrait needed to be above or below 7 to be effective at removing surface dirt so that the conservation project could be successful.
I first tested a small area on the edge of the painting with water: tap, saliva and deionised. The test swabs showed no lifted dirt.
Using buffered water to stabilise the pH value of the solution, I first tried a chelator (citric acid 0.5g) in 100ml of buffered water. The test swab did not remove any dirt.
I then tried a combination of chelators (citric acid and EDTA) mixed with buffered water. This created a solution with a pH value of 6. Again, the swab showed very few traces of dirt.
As the lower pH solution was ineffective, I tried a solution with an increased pH value. By combining citric acid and boric acid in a buffered water, I produced a solution with a pH value of 8. Again, there was no dirt visible on the test swab.
I next tried adding a surfactant to a solution of buffered water and a chelator (EDTA). This was slightly more effective at removing dirt, but also seemed to be lifting the paint. Due to this undesirable effect on the paint and to concerns about the potential damage that could be caused by too much water exposure, I decided that the amount of dirt removed did not justify the risk.
I made several attempts to remove the white paint splatter with topically applied warm water, on the assumption that the paint was some sort of decorating emulsion. This was not effective so I tried to mechanically remove some of the thicker spots with a scalpel after moistening them with warm water. The paint was too hard and the force required even to partially remove the spots was causing damage to the original paint layer.
The Varnish Layer
As I was uncertain whether the painting had been varnished, I did not risk applying a solvent to the canvas. However, I did test the shiny areas to see if they could be surface cleaned. To reduce the impact of water exposure I prepared a gel by mixing methylcellulose (KlucelG) with buffered water and added a chelator EDTA (12.5%) and TAC (12.5%). The test swab showed that no material had been lifted. Based on this outcome I would assume that if there was a varnish present then it was likely to be synthetic. Curiously, some areas of the painting – the face and dress – are entirely matt.
After removing the surface dirt, I was able to examine the painting in UV light. The purple hue supports the theory that a synthetic, modern varnish has been applied but has become patchy due most likely to environmental degradation. There is a possibility that someone cleaned the varnish from the dress and face in from a previous attempt to undertake this conservation project, but I was not able to remove any of it with the solutions that I tested. It is very clear that it is not mastic or dammar that has been used in the past.
Retouching
Using watercolours so that any changes I made would be reversible, I covered each point of white paint splatter. The retouching is confined exclusively to the disfiguring spotting.
This painting was a challenging conservation project, as very little was known about it. Painted by an amateur, it wasn’t initially obvious if the artist had used oil or acrylic. The type of paint that had disfigured the surface was also unidentifiable. It became clear that the only way to restore the painting to a state in which it could be enjoyed was to simply cover up the blemishes. The client was offered the option of a newly applied layer of varnish to even out the degraded varnish layer, but she felt that she would prefer to keep the matt effect that now dominates the portrait’s appearance.