Conserving botanical paintings - upcoming demonstrations in the Marianne North Gallery
Conservation at Kew does not stop at plant species and the environment. Kew’s team of paper conservation staff are currently working on the final stages of a two-year project to preserve the paintings lining the walls inside the recently restored Marianne North Gallery. I am part of this team working on the 832 oil paintings on paper to ensure they last long into the future. One of my colleagues, Helen, has also blogged about our work.
Alongside our practical work we hold monthly gallery talks in the Marianne North Gallery about how we conserve the paintings. This month we plan to demonstrate the most common practical treatment to help explain how we have been improving the condition of the paintings. I will now go on to describe the treatment and why it is carried out.
Close up of flaking paint
When they first went on display between 1881 and 1882, the paintings were originally stuck onto low-quality boards to keep them rigid in the frames. Today these boards have become brittle and discoloured from acids transferred from inside the wooden frames. This acidity will have moved through the board and onto the back of the painting which would eventually cause the paper to weaken and the paint to become unstable. The main task in treating a painting is to remove this backing board with care so as not to damage the painted surface on the front.
It is important to consider the nature of the paint and whether it is stable enough to withstand backing removal. This treatment has to be carried out with the painting placed face down so any loose or flaking paint needs to be made secure first using a type of adhesive. During backing removal the painting rests against a cushioned support of felt covered with a smooth polyester film similar to tissue paper to prevent abrasion. Light weights hold the painting in place.
We use surgical scalpels to gradually remove the board taking it down layer by layer. These are precision tools which ensure care and accuracy in direct contact with the painting. The surgical blades range in shape and size depending on the stage within the treatment and the area being removed. Where there is an inscription or drawing on the board we retain it to keep with the painting.
Backing removal using a surgical scalpel
The final layer of board stuck against the back of the painting is known as the facing paper. Deionised water is applied in small amounts using cotton wool to soften the glue and paper layer and allow it to be removed using a small spatula.
Removing the final layer of backing board
Find out more...
If this has intrigued or baffled you and you want to know more, come along to a free drop-in practical demonstration taking place in the Marianne North Gallery from 2.30 - 4pm on Friday 27th August.
We look forward to seeing you there.
- Rebecca -