How do we clean a 600-year-old painting? | Uccello's Battle of San Romano | National Gallery

My name is Paul Aykroyd from the National Gallery's Conservation Department and I'm just going to briefly talk about this painting which is Paolo Uccello's Route of San Romano or the Battle of San Romano as it's also known. It's one of a series of three paintings. This one is supposed to depict the early scenes of the battle in the morning. There's another painting in the Uffizi in Florence which is the same battle going on in the afternoon and then there's another one in the Louvre which is painted in the early evening. And this arrived in the Gallery's collection in about 1857. It was last cleaned and restored in the early 1960s and in the intervening time between then and now the varnish has yellowed quite significantly as you can see around here in these areas, these blue and purple areas here. And also the retouchings that they used at that time have darkened quite a lot, they've changed. A lot of the original colours that Uccello used have changed over time, particularly this sort of grey colours that you can see here and over here. This is a darkening of vermilion, the red pigment vermilion. So all of this would have looked like this sort of red colour here. And similarly here, all this sort of parts of this banner here which are painted red would have been a very bright red and there would have been quite a difference between the armour and the banner behind. A lot of these greens have also darkened over time so there has been quite a lot of shift in the sort of colours of the painting which we cannot do anything about during the restoration process, that's just part of the ageing of the painting. This series of paintings was commissioned by the Bartolini family in Florence. Originally they had arched tops and then somewhere around the mid-1480s the paintings were appropriated by Lorenzo Medici. He took them to his palace in Florence, had someone put in infilled pieces of new wood and painted these in the corners and then cut off the arched tops and that's happened to all three pictures. This has come up to conservation for cleaning to remove some of the discoloured varnish or all the discoloured varnish which you can see the marked differences that that cleaning process makes. The white horse here compared to this area which is not cleaned at all which looked quite yellowish and grey. The other areas that have changed will change quite significantly is the silver leaf here which Uccello used in the armour. The abrasion in those areas have been retouched with an aluminium powdered paint in a synthetic medium. It doesn't look very good, it's changed quite a bit, it's blanched and so some of this will be retouched to a much better level than it was before. So these will look a little bit more strongly three-dimensional. Again this sort of area here of abrasion that will have to be retouched and all these losses across where the joins in the panel are as well. Obviously this area of the flag here will come out to be a lot whiter in colour than it is now. There's also quite a large damage in this area, well not so much a damage, this was a piece where a new piece of wood was let in originally. So there will be a lot of restoration that will have to come off and be redone in that area. In this area here where the trees in the background look quite fuzzy and that's because there's an awful lot of restoration there and that will have to be removed and done a little bit more precisely than it was done in 1960. The main figures here of Niccolò da Tolentino, the Florentine head of the forces, his face has lost an awful lot of modelling as has Hage's face as well and we will have to do something about that modelling to make it look a little bit more three-dimensional during the retouching. So you can see these two faces look quite green, that's because they have the Terre Verte under-modelling showing and a lot of the top layers of paint have been rubbed away in previous cleanings. So these will have to be, the modelling will have to be re-established to some degree, not totally, that would be impossible, but they will look less green once the restoration is finished. So the cleaning process which is pretty much half way through now will take another month or two to complete and then it will go to colleagues in the scientific department to do some sort of scientific investigation of parts of the painting and once that's complete the painting will come back for the retouching which will take about a year to 18 months to complete. If you want to find out more about this painting and others in the collection please click here or here and thank you very much for watching.