Melanie Caldwell on conserving Reynolds's paintings

Paintings conservator, with more than three decades' experience working on the Knole collection

Interviewed by Veronica Walker-Smith in January, 2017

Paintings conservator, Melanie Caldwell, has been involved in conserving many paintings at Knole over more than three decades. During the 2013-2019 Inspired by Knole project, she was interviewed at the start of work on a very important example of Sir Joshua Reynolds’s portraits on display in Knole’s Reynolds Room. Melanie describes the condition of the painting of Huang Ya Dong [also known as ‘Wang Y Tong];  the latest conservation science investigations to be made; and the involvement of Reynolds’s assistant, Rising.

Condition of Huang Ya Dong before conservation treatment

He’s had a history of conservation issues almost since when he was painted. And we now know that Reynolds’s assistant, Rising, came back to Knole within 30 years after he was painted, to work on paintings in the Reynolds Room. In fact, we found Rising’s name on the back of the stretcher. So we know that this was in fact one of the paintings that he worked on.

Since it’s been in the National Trust’s collection, it has been noted to have flaking paint issues and really, a mechanical failure of the original canvas and ground. And it’s been treated twice that I know of – in the 1980s and 1990s. And when I became involved in the collection, however many years that was, it was noted to be flaking again then. And that has got significantly worse, and that’s also related to the environment it was in: a very high relative humidity and the cycling environmental conditions over decades.

So, it is also a very important painting at Knole, particularly in the Reynolds Room, and was high on the priority list and when we were treating paintings in situ, the flaking was such that it couldn’t be done in situ. So, it was sent to the liner’s studio – Trevor Cumine –  who has given a linen lining with Beva 371 conservation adhesive and that’s been very successful.

It’s now back in our studio, post-lining, and isn’t flaking. And Trevor has been able to deal with some of the textural issues which occurred because the paint was flaking.

At this point, we are in January 2017, and Knole is due to re-open in March. And this wouldn’t be a treatment that I would want to rush anyway; but that is compounded by it being by Reynolds. There’s been a lot of research by the Wallace Collection and the Tate over the last 20 years, that has examined Reynolds’s paintings. And they have problems with solubility. So, Reynolds added a lot of things to his paint, namely bitumen, wax, resin; they make them potentially difficult to clean. He also re-worked his paintings and as we know, as at Knole, he also sent his assistants in to restore them quite early.

Cross-sectional paint analysis and cautious approach

“The cross-section will be the most useful as a starting point. The Courtauld Institute have a plate, an X-ray plate was taken of Wang Y Tong in the ‘90s, early 1990s. So, we’re just getting hold of that and trying to understand what sort of treatment happened at that point.”

“That’s the plan: is to get the sampling and the investigative work underway, Wang Y Tong can get back to Knole for the opening. And then in November when the house shuts, we’ll have all the information at our fingertips. And then we can make informed decisions about how far we want to go with the cleaning and the restoration. And the other thing which has been thrown up in looking at the painting is that there does exist a print of this painting, from I think it’s around the 1830s. The image looks in far better condition. So, potentially, particularly on the left-hand side, the foliage and the landscape through that window opening – it’s a far better quality in the print so we’re then at the point where we’re now thinking that a later cleaning has been responsible for some of the damage that we now see. You know, I’m talking about – there’s a lot of damage around his hand, and quite possibly in the red sleeve where on the print it almost looks like there might have been that sort of quilting which is quite usual for .. “

Interviewer: for warmth? 

MC: “Yes, for that sort of oriental fabric. So, at the moment, I’m planning to go to the British Museum to actually have a look at the print in person, to get as much information because it’s never quite as good online, obviously.

And then, yes, we’ll start the investigation to try and work out not only actually how far we clean, but it will inform the restoration too. And you know, how much we should be thinking about removing here – if it turns out that some of the existing paint in the landscape is restoration. But the watchword would be ‘cautious’ because obviously I think, the bottom line would be, we would leave anything that was not clear.”

His assistant, Rising; Reynolds's technique

“We don’t know very much about him [Rising] at all. In fact, this is all very recent research which has been done by Alexandra Gent who, as I said, will actually carry out the sampling and paint analysis because she’s very familiar at looking at Reynolds techniques and paint samples of his paintings.

And she, in the course of her research at the Wallace, found that Reynolds was restoring paintings within five or ten years. And also, that he seems to have had a phase when he was adding things; and his whole view was that he was trying to re-create Old Master technique. So, when these paintings were painted, the colours were incredibly rich and saturated. And then he did actually stop, he certainly stopped using bitumen because the drying problems were so apparent. I think we’ve got bitumen – we’ve certainly got drying crack problems at the top right-hand corner. So, he altered his technique. There’s probably a peak period when the paintings are in particularly poor condition and this [Wang Y Tong/Huang Ya Dong] clearly falls into that category.”

Unpicking many layers, using conservation science

So, there are many layers to un-pick before you would attempt to clean a painting. So, together with the staff at Knole and with Tina Sitwell, paintings conservation advisor at the Trust, we’ve been discussing how best to go forward with the cleaning. Because clearly, it needs cleaning. It’s got multi layers of dark, discoloured varnish, wax, the remains of consolidants from people who’ve tried to treat the paint. And we would want to at least try and see if we can clean it.

The cleaning tests that I’ve done, suggest that we will be able to do some, some varnish removal. So I’ve done a cleaning test up there [indicates area] which was fine. So, we will be able to parts of this painting if not the whole thing. It is possible to remove some layers. That isn’t down through all the varnish layers. I’m showing a window in the varnishes that I have made with the solvent cleaning tests.

So, the plan at the moment is to take some very small paint samples and to use conservation scientists to look at the layer structure so we can ascertain what might be Reynolds and what might possibly be Rising if he re-worked it, and also what might be later restoration. And it will also enable us to do pigment identification, to see what pigments might have discoloured.

Cross-sectional analysis would be the starting point, and then to see what you would need.

At the moment we are talking to the Courtauld [Institute of Art], and also to Alexandra Gent who did the research on Reynolds at the Wallace Collection, and is also doing a PhD and works part-time at the Tate.

Melanie's experience with conserving Reynolds's paintings


“There isn’t a ‘usual’ [treatment process] with Reynolds. I mean I worked on the self-portrait that’s at Knole; and funnily enough I also worked on Miss Axford [Portrait of a Young Woman] a long time ago when I was a student at the Courtauld. And then I’ve also worked on other 18th century paintings by  artists who were also adding things to their paint, although I have to say Reynolds is in a league of his own.

And there isn’t really a one-system fits all [for Reynolds] in terms of what you’re removing. But I would say for Wang Y Tong, it’s very typical of the Knole Collection, in that no full treatments have gone on there over a long period of time. So, there is a very large build-up of varnish layers and consolidation from in-situ work, that adds to the surface problems. So, it’ll be very exciting to actually get through that and see what’s below.”

This page was added by Veronica Walker-Smith on 06/08/2023.

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