How do you stop the copper from reacting?

January 2nd, 2017

People often ask me about the longevity of my copper paintings, particularly about whether the copper will continue to react. It’s a question I am always happy to answer, and thought I would outline it in detail here. As an artist, my aim is to produce work that will outlive me, the buyer and hopefully generations to come. Buying original artwork is an investment, and I certainly like to think that works I have purchased will be handed down to my children and grandchildren someday. I’m sure many of us think the same.

There are archival challenges for any artwork. Museums and galleries take great care with how they store and hang work, and even in spite of all their precautions artworks can sometimes need restoring. In 2015, art restorers at the Metropolitan took 10 months repairing Charles Le Brun’s painting of Everhard Jabach and his family.

For my copper paintings, some archival considerations are the same, others are unique to the material. Some are my responsibility as the artist, others the buyers once the work gets home. Of course, much of it is common sense and if care is taken when transporting, handling and displaying the work should remain the same for a long time to come.


My copper paintings are created using chemical reactions. I speed up and enhance natural processes which would usually occur over the course of many, many years if the copper was exposed to the elements. Think of copper statues which have lived in public parks and squares for hundreds of years, oxidising and turning green over time. When using the chemicals I take care to neutralise the reactions, which means that they won’t continue to change the copper. Where there is pure copper leaf on the canvas, it is possible that natural reactions could still occur. However if you follow the advice later in this article, it is unlikely that it will.

blue powder close up
The reaction shown here is the one which initially proved difficult to preserve.

Finishing the work

This has been one of the biggest challenges I’ve encountered in developing this unique painting technique. When I started thinking about finishing my aim was to create a protective layer over the copper to protect it from damage or tarnish. However, one of the chemical mixtures changes the colour of the copper whilst also turning it into a powder and this proved highly problematic. I tried various varnishes and resins that brushed on, poured on and even sprayed on but none of them worked. They protected the copper wonderfully and created a beautiful shiny finish, but the varnishes and resins all mixed with the powdery reaction and changed its colour. That wouldn’t do.

Eventually I decided to try a pastel fixative, and having read a bunch of reviews went for Winsor & Newton’s professional fixative. Boy, oh boy would I recommend it! It has worked brilliantly! This spray fixes the powdery reaction to the canvas, making it less likely to brush off, without changing its colour at all.

This method of finishing the work gives the copper an extra layer of protection, and is something I have spent many weeks gruelling over to get right. It’s so important to me that the work is as protected and long lasting as possible.


When working with the copper leaf, I always make sure to wear gloves. This is because the natural oils and acids in the skin can cause the copper to tarnish over time. I’m not suggesting you wear gloves every time you move the work, but care should be taken not to touch the copper unless necessary.

Lighting and Atmosphere

These factors apply to any form of artwork. No painting benefits from direct light, as prolonged exposure can cause changes in colour pigments. Diffused natural or artificial light is ideal. Extremes of heat, humidity, cold and dryness should also be avoided. I ensure that the paintings are stored and exhibited in a manner which protects them from exposure to poor lighting or atmospheric conditions.


As someone who dusts once every six months (cleaning isn’t my favourite activity) this is something I have to remind myself of. All artwork needs dusting from time to time, but the copper paintings need dusting more regularly as the myriad of chemicals in the dust can cause tarnishing if left too long.

EDIT [24/09/2018]: I am continually researching new preservation methods regarding the treatment of copper. I have recently become aware of Paraloid, a product similar to a resin/adhesive which has a very low reactively and forms a protective layer between the copper and the atmosphere. I use this on areas of the artwork, such as the edges, which are more likely to be handled, as an added protection.

Hopefully this article reveals the actions I’ve taken to protect the work as well as possible, and answers some questions about the chemical reactions. The basic guidelines outlined here will go a long way towards ensuring the longevity of any artwork. Any more questions, please don’t hesitate to ask. Leave a comment below or drop me an email at . Further more, I always keep my ear to the ground about other ways I can preserve the work, if you have suggestions, I am happy to hear them.

Winter copper painting
Due to its small scale and colour palette, Winter is the only painting which successfully survived being coated with a gloss varnish. The effect is beautiful.

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