Art Conservation Project: Watercolours of an Early Ontario Naturalist
In 1917, Toronto Public Library acquired 226 drawings of birds and mammals by William Pope (1811–1902). Pope lived much of his life in what is now Ontario. He was Canada’s first artist-naturalist of European background. Learn more in our post about Pope.
These beautiful watercolour and ink drawings date from the 1830s to 1860s.
Back in 2009, our conservators created a long-term preservation plan to treat and properly store these pieces of history. While our conservation lab was temporarily closed due to the COVID-19 pandemic, we put together this summary of the process.
Condition of the works
A survey of previous ad hoc treatments was completed, noting how many of the watercolours were still matted and framed, and how many had been unmatted for exhibitions in the TD Gallery at Toronto Reference Library.
The watercolours were matted and framed with acidic materials. Acidic mats and backing boards stain and weaken the watercolours.
Of the 226 drawings, 144 had never been treated.
A multi-staged treatment plan spanning many years was made. It allowed our conservators to gradually work their way through the treatments in between their other work.
The individual watercolours were painted on heavy-weight, high-quality wove paper. Unfortunately, they had been mounted to an acidic backing board with an acidic window mat glued to the front of the watercolour with animal glue. Treatment included removing the matted watercolours from their frames, followed by mechanical removal of the window mat and caption.
Once the window mats were removed, the water soluble animal glue could be removed. This first stage took about two and half hours per drawing.
A common condition issue is mat burn, a reddish-brown linear stain formed where the mat window opening contacts the watercolour paper. Acidity stains such as mat burn are not easily reduced. That's why good quality mat board is always recommended for valuable works. No attempts were made to reduce the mat burn stain.
The next stage is the most tedious: completing a backing removal of the acidic mounting board. This is a very slow, precise process, carefully thinning the layers of the backing board mechanically. Estimated time for completing this stage was four hours per watercolour drawing.
Next step: humidification and flattening. The watercolours are placed in a shallow tray atop a water vapour source and allowed to take on moisture for a limited period of time. Once the watercolour is limp and relaxed, it is carefully transferred to a cotton blotter stack to dry under weight for a number of days.
And then the treatment is complete!
A revitalization of the project in 2016 focused on unframing and removing the window mats on all the remaining watercolours. These two procedures are relatively quick, and were completed in a number of weeks. Since adhesive reduction and backing removal are relatively lengthy processes, they will be performed at a later time.
Now all of the watercolours have reduced contact with acidic materials, which is key to preserving them for current and future research.
Storage and access
Prior to the completion of unframing, the collection was spread across different locations. Now the collection is together again.
All of the Pope artworks have been placed in individual folders and temporarily housed in archival boxes. This has a double benefit: the watercolours are more accessible than when they were framed, and the dark storage helps keep their colours vibrant.
We also digitized several of the works for better access: check out high resolution versions on our Digital Archive!