Philips Wouwerman: Quiet Reflection and Scientific Investigation

Philips Wouwerman, Travellers Resting, c.1648/50, before treatment; Jacques Aliamet, Roadside Rest in Spain, 1750, print reversed; and Philips Wouwerman, Travellers Resting, c.1648/50, after treatment. All works National Gallery of Canada, Ottawa Photo: NGC and RCL, NGC

How often do you take note of your quiet surroundings? Perhaps, you pause every day for a moment to admire an object or work of art, in your home or your surroundings, discovering something new each time. Philips Wouwerman’s Travellers Resting would have provided an opportunity for the same form of quiet observation. The small-scale painting depicts a scene from daily life: travellers at day’s end. The picture would have been ideal for display in a Dutch home in the mid-17th century.

Donated to the National Gallery of Canada in 2019 (see related article by Christopher Etheridge), the painting came to the Gallery's Restoration and Conservation Laboratory for examination and treatment, prior to being put on display. Painted in oil, the work is on a single-member oak panel. As the support is in good condition and required only minimal attention, the treatment focused primarily on the painted surface. The discoloured, natural resin varnish and previous restoration campaigns were removed carefully, enabling proper assessment of the original paint layers. The foreground depicting the travellers is in excellent condition. Previous cleaning campaigns, however, had caused changes in the mountain, the cloud formations and the sky, resulting in loss of depth and subtle transitions. The changes also revealed a pentimento – a change made by the artist – in the mountain. Finally, the once-blue pigment used to create the darkening clouds in the upper right of the evening sky has experienced decolourization. This decolourization and the uneven thinning caused by subsequent cleaning cycles has created uncertainty in the sky and muddled the interpretation of the picture’s time of day.

Philips Wouwerman, Travellers Resting, c. 1648/50, before treatment. Oil on oak, 32.5 × 36.3 cm. Gift of Alex and Wanda Fallis, Ottawa, 2019. National Gallery of Canada, Ottawa Photo: NGC

Smalt is a blue pigment made of cobalt-containing glass. As a transparent pigment, the strength of this colourant is dependant on the amount of cobalt present and the coarseness of the grinding process: finely ground smalt makes a weaker blue. Although some artists knew smalt has a tendency to decolourize and grey after fifty years or so, it continued to be used in the 16th and 17th centuries as a more cost-effective alternative to ultramarine. The degree of change can vary, even within the same painting. Decolourization depends on the amount of potassium carbonate added as a flow agent during manufacturing: smalt that has a greater concentration of potassium to cobalt does not decolourize to the same degree, but the potassium leaching into the oil medium surrounding the fragments of glass may cause it to go brown. Either way, smalt always changes.

Without early photographic records of the painting, it can be difficult to determine the exact amount of change in the appearance of the paint layers. Fortunately – to make this conservator’s task easier – a French artist, Jacques Aliamet, made an engraving of Travellers Resting some 100 years after the Dutch master made the painting. What is even more fortunate is that a print of this engraving was donated to the Gallery, along with the oil painting, and was restored in the summer of 2019.

Jacques Aliamet, Roadside Rest in Spain, 1750. Etching and engraving on laid paper, plate: 35.3 × 40.8 cm. Gift of Alex and Wanda Fallis, Ottawa, 2019. National Gallery of Canada, Ottawa Photo: NGC

Aliamet’s engraving was very useful in the course of the painting's conservation treatment. Tasked with representing ranges of colour simply with the thickness and density of interwoven black lines, engravers develop a keen understanding of tone across the relative hues, and Aliamet’s engraving is a deft example.  By taking digital images of both works and superimposing them using computer software, we were able to compare the two closely and ascertain that the level of accuracy achieved by the professional engraver was extremely high. It is clear that Aliamet dedicated some time to quiet contemplation of this painting while reproducing it: he rendered relative scale and detail faithfully, and was impressively sensitive to Wouverman’s tonal nuances. The high level of accuracy means the print could be considered as effective primary source material to help guide the retouching campaign.

Philips Wouwerman, Travellers Resting, c.1648/50, after treatment. Oil on oak, 32.5 × 36.3 cm. Gift of Alex and Wanda Fallis, Ottawa, 2019. National Gallery of Canada, Ottawa. Photo: RCL, NGC

To determine the level of restoration required, this stage of the treatment was conducted carefully and slowly, once again returning to the quiet state of observation for which the painting was originally intended. Sitting together, the conservators and curator responsible for this work studied the painting at various stages during the “retouching” process, the phase of the restoration where paint loss is compensated for. It was during these collaborative moments we decided upon the sequence for the restoration, reflecting after key areas were completed and allowing the slow re-integration to clarify the next steps.

In the print, it was clear that the engraver was highly attuned to faithfully reproducing tonal changes in the sky and rendered the onset of night by darkening the sky as the sun was setting. Our strong suspicion was that Wouwerman’s sky would have had a similar tonal range, and it would have once been much darker and bluer on the right-hand side. Since there were so few remaining fragments of decolourized smalt, however, there was no compelling, clear evidence that this was the case, and we were ethically inhibited from pursuing this possibility in the restoration.

Digital manipulation of Wouwerman's painting Travellers Resting, emphasizing the loss of smalt, and merged with Ailment's print, indicating the possibility of a darker cloud formation at top right.

Digital manipulation of an image does not resolve these ethical implications, but it does give an intriguing glimpse into what may have been. The final decision for the level of retouching was to create a cohesive appearance between the retouchings in the areas of cleaning damage and the surrounding original paint, returning a version of the atmospheric mood Wouwerman was so skilful at creating.

With the restoration treatment complete, the picture can return to the life of quiet observation and reflection to which it had been so accustomed in previous home settings. Travellers Resting awaits your return to the Gallery.


See also the article by Christopher Etheridge. Share this article and subscribe to our newsletters to stay up-to-date on the latest articles, Gallery exhibitions, news and events, and to learn more about art in Canada.​

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