Watercolour Painting Preservation

Watercolour Painting Preservation

There are 2 major groups of attack to watercolour paintings:

1. Acidic moisture bleaching the painting surface or acidic moisture penetrating through the back surface attacking the paper which causes yellow spots appearing on the paper.


2. UV light bleaching the paper.

For case 2 it is easier. Just keep away from direct UV or direct sunshine. There is anti-UV glass which more advanced frame shop can provide. The rule is : Strong lighting is always harmful to both oil or watercolour. The UV light and heat and 2 energy source that could accelarate any chemical reactions.

Case 1 is a more common headache to all collectors. My rule is : Change the painting environmental condition.

I learnt this from corrosion engineering idea in school. In corrosion engineering, it is called sacrificial anode. Since corrosion always happens, we provide a material for it to corrode. Therefore, the original object like a big ship in the sea will not corrode.

So these are the steps:

First make sure the frame environment is dry before fitting in the painting

Next prepare all protective layers that change the whole environment against acid moisture.

• Get a larger piece of acid free watercolor paper


• Gesso it with oil paint acrylic ground


• let it dry for at least a day


• Use this protective layer and place behind the watercolour painting


• Matting should be acid free museum grade if possible. Alternatively, regular grade mats can be coated with transparent gesso at the back. That makes it similar to acid free mats.

Ensure everything is dry, then seal the frame tightly. Minimize regular adhesive in contact with painting paper.

The sacrificial piece of watercolor painting can last 3 years. Mats should last about the same length of time. So, change them after every 3 years.

**Wooden backing is one of the major source of acid moisture. Gesso it can block certain level of its acidity.

** Acrylic Gesso has some alkaline content in it. Ammonia is one of the common content. That neutralizes acids.

If you have watercolour paintings that are already having problems, some fine art restorers can help reduce the problem. Eliminating it might not be possible.

Feel free to contact me, if you have more questions or anything to discuss.
Email me: ngwoonlam@yahoo.com