Hello, my name is Hayley Tomlinson and I'm the conservator responsible
for treating Rosa Bonheur's painting, The Horse Fair,
in the Conservation Department at the National Gallery.
The painting is actually in a very good condition
and the treatment is therefore quite simple, quite straightforward.
What I'm doing is removing the discoloured and aged varnish layers
which mask the original condition of the painting
as you can see here.
The varnish that was applied is a synthetic varnish
which, we believe, was probably put on in the 1950s
and also incorporates a great deal of wax.
The difference here,
as you can see in the sky, is that the varnish
has gone very yellow and dark, so in these areas which have been cleaned,
the sky now appears much bluer and lighter.
Lower down the painting, in the foreground and around the horses,
it's really about the tones.
You can see here that the tones are greatly reduced or compressed,
and that much of the illusion of depth and recession is lost.
So this is, you know,
we really get to see the painting afresh by removing
these discoloured varnish layers.
So all these things are going to come out as I continue cleaning the painting.
And the other great gain with this treatment,
which we hadn't expected but which is very pleasing,
is to rediscover the texture of this painting.
The artist, Rosa Bonheur, clearly really loved to experiment with her brushwork
so, in the sky, you can see the brushwork here is very bold and vigorous,
and then, in the horses, these fantastic horse coats are very fine
and down below, where she's wanted to show the ground
as being very dry and dusty,
the paintwork is really broad and rough.
So all of these
is clearly a very important characteristic of her technique.
All of which we couldn't appreciate before
but which is now being uncovered.
To remove the varnish, in this case,
I'm using a mixture of two solvents
which I've combined in a particular ratio
which allow me to work through the varnish in a steady and controlled fashion,
not too fast or too slow.
And I make up the mixture
in a small quantity which I place in a stoppered jar on my trolley
and, when I'm ready,
I roll a swab.
So it's very soft cotton wool
and a sort of flexible swab stick.
And I dip the swab in my solvent
and then I work, rotating the cotton wool swab
gently over the surface of the varnish.
And you can see, I'm rotating it so that
I'm using all of the surface of the cotton wool.
Removing this varnish.
And I should say, as well,
that the solvent has a very important lubricating action,
as well as solubilising the material,
it does also kind of cushion the swab.
As a conservator, one has to be constantly mindful
not to cause any sort of mechanical abrasion
and this sort of helps with that.
And then, when the swab is completely spent,
so all the solvent is more or less gone,
and there's lots of brown material on that,
I then remove it
by disposing of it in my swab pot.
In this instance, with this particular painting,
I probably need about four or five swabs to get down to the surface,
and there are various tools that I can use so I know exactly where I am.
One of the most useful tools is UV light.
This is a small but very powerful UV torch
and because the varnish fluoresces
but the paint, in this case anyway, doesn't fluoresce at all,
I can see exactly where I am and how much varnish is left.
I always have very good magnification and lighting,
and even feel is a very useful aid.
I can feel the difference very easily between varnish and paint,
and these very flexible thin swab sticks
help us to know exactly what's going on at the surface.
Having said that, I only use four or five swabs,
at about the third swab, I go through a brief phase of whiteness,
broken up residues that just haven't fully solubilised yet,
and I need one more swab to get through that and then, that's off.
And then, when I'm right down at the surface,
the very last swabs, I use a completely different action.
Rather than moving the swab around like this,
I roll it more like this,
so there's absolutely no abrasion or rubbing of the surface at all.
Because I'm using a very loose wet swab,
it allows it to reach inside the depressions in the brushwork
and pulls them out.
I should say, it doesn't matter if there are a few tiny wisps of residues left.
Obviously, broadly speaking, I do want the clean to be as even as possible
so that it's going to last longer
and the painting will stay looking good for longer,
but if there are a few tiny traces here and there, little bits of residue,
that's OK, that won't matter.