It is surprising how resilient good quality paper is. This book was in very bad condition. By repairing the pages, it was possible to rebind the book.
Sometimes a stain needs to be removed from a painting using solvents. Firstly, the stain is identified, then a solvent is identified to remove it. A stain cannot always be removed. It may have the same solubility parameters as the medium.
Poor mounting can easily damage paper. This print is painted in heavy gouache so it will never be flat, but by placing it in a solid museum-quality mount (made from rag paper), it will not deteriorate with acidity.
Paper often needs flattening. Sometimes it is just a crease in the corner; at other times, it is more drastic like this piece. It is possible to make the majority of paper flat and there are many methods.
Backing removal is a common application; often pictures are lined in old or inferior material, creating a build up of acidity. It is not always possible to save the support. It may need to be damaged to save the picture. This pith painting was backed with silk and stuck down with animal glue. Enzymes in a rigid gel were used to break down the glue and take the painting off the silk back without any damage. Further stains were removed safely from the front of the picture.
For this project we were asked to remove the watercolours from a book, flatten them and place them back in the same Album. The wash-line was very sensitive to water and the paper was stuck down with animal glue. We used Agarose to soften the glue and lift the watercolour from the page. This method can sometimes be used, to effectively save both the painting and its support.
Paper can be washed to remove stains. Some media are very sensitive to water or solvents, so everything is tested before carrying out this process and then washed accordingly. Foxing, caused by mould or iron in the paper, is a common sign of deterioration. Washing can often improve this.
When paper has numerous tears and is badly deteriorated, it is possible to line it to give it support. The methods we use were invented in Asia, for example using Japanese paper that is light and strong.
Media can start flaking with age and begin to come away from the page. It then needs consolidation. It is important to keep the right sheen, weight of the material and saturation of colour, so the result is invisible.
One can learn a lot by analysing pigments and support. I was asked to identify the process of this print: was it an original sugar-lift aquatint or a four-colour process copy (fig:1) . By looking at the ink under the microscope, I could see at 40x magnification that the dots were scattered over the whole area (fig:2) and not just on the mark, like that made by ink (fig:3). At 400x magnification, I could start to see colours in the black ink identifying the CMYK process (fig:4).
Some pieces need to be retouched so you can read the image coherently. In one of the examples, the retouching blends with the repairs, whilst the other one is invisible.
Paper can easily tear with age. A good repair should be strong and invisible from the front and blend into the back of the page.
This fan needed large infills. The pattern was copied from other areas, and the background colours matched.