Watercolour paintings and works on paper are inherently fragile items. The challenges they face can be therefore quite different to more robust oil paintings on canvas and panel.

There is, however, always a solution to the problems that they face. Whether a watercolour has foxing, or a map is torn, professional conservation can rectify these issues and offer comprehensive protection.

Keeping a close watch on watercolours and works on paper is important – especially if you have recently come into ownership of the item and have limited information on its provenance and history.

We’ve put together some detailed examples of common damage that these artworks can be susceptible to, so you can look out for any such similar signs.


It is more common for works on paper to be glazed, as opposed to oil paintings. If they are glazed using conservation grade materials and UV protective glass they should be well looked after. If a work on paper is not glazed – or even unframed – then it is more likely to attract contaminants, dust and dirt onto the surface.

If an artwork has become discoloured, it can be particularly evident if it appears that the colours have become dulled. Looking on lighter areas of the painting, such as the sky or sea where the white and light blues have lost vibrancy, can be a good indicator.

Smoke and nicotine damage

Of course, surface cleaning can also be required perhaps if a painting is damaged through smoke or nicotine. A yellow or grey-ish hue obscuring the finer details of the painting may be suggestive of this.

If your painting does present extensive discolouration, measures can be taken to counteract the damage. Depending on the severity, a surface-level clean may be sufficient or a more intensive ‘float wash’ method will instead provide the required treatment. When a painting is washed in the solution to remove the contaminants and pollutants, the treatment does not impact on the colours and pigments of the painting or cause them to ‘run’.


Reddish-brown spots that appear on artwork are identifiable as ‘foxing’.

These rusty looking patches are caused by bacteria or mould growing on acidic paper. When this paper reaches a certain level of acidity and combines with humidity when it is high in the environment, this can cause the impurities and mould to thrive and the reddish stains then appear.

Foxing can be treated by utilising specific washing treatments which flush out the polluted acidic elements on the paper. Alongside this, usually to remove foxing completely you need to use a conservation standard bleaching agent. Similar to when a painting is cleaned through being washed in solution, treatment for foxing does not compromise or damage the paper support or pigments.

You can read more about foxing in our article How to treat foxing in a watercolour

Acidic damage

If the supportive materials used on artwork, such as the backing or mount board, are acidic, damage will present itself through yellowed discolouration and staining. The acid leaches through from the back of the artwork, where it has had the most contact with the acidic materials, to the front.

In such instances, cleaning the artwork to remove the pollutants is key, and all inappropriate materials should be replaced with museum-grade conservation materials.


Unframed works on paper are particularly susceptible to damage due to being unprotected. The fragility of the thin paper can easily be torn if knocked or dropped. If artwork has been rolled up or folded for some time, perhaps if it is a map or certificate, its structure is weakened and it becomes most fragile along the crease lines. This can therefore often lead to tears.

Any tears and missing areas in works on paper can be repaired by using liquid paper pulp or by being lined with Japanese tissue. The fragility of the materials involved makes this a delicate and careful task. Once done an artwork will be well strengthened – particularly if the lining was required to stabilise the most delicate artworks.

If you have a damaged watercolour painting or work on paper and would like our advice for restoration, please contact us for our no-obligation advice.