What I’ve learned: Simon Gillespie, art restorer
Simon Gillespie — who has spent 30 decades restoring and conserving works for leading museums, English Heritage and Christie’s — on the science, the surprises, the gut reactions and the never-ending challenges of his trade

Art restorer Simon Gillespie in his London studio
Old Master painters knew their craft. They knew how to handle their materials and worked with consistent techniques that have withstood the test of time. Currently about 70 per cent of my work is restoring Old Masters, but people are increasingly bringing in modern and contemporary works — it’s a whole new ball game when you’ve got materials like nylon and chocolate involved.
You need a solid plan before you even touch a contemporary work. I was on a course recently about cleaning contemporary works; it’s important to keep up to date. I also find myself advising living artists on how to paint for longevity.
It’s better to buy a grubby picture. If it has already been fixed up, you don’t know what’s been hidden. Dealers flock to grubby pictures like bees, especially if a work is listed as ‘by unknown Dutch school’. Everyone wants to find a signature under the dirt.
The UK smoking ban had a profound impact on the industry. I am being light-hearted, but in the old days we would spend hours cleaning cigar smoke off paintings, and the whole office would smell of tobacco. That all changed when the smoking ban came into force in 2007.
In general, I never take a picture back to its original, pristine state. I like a patina of age on a picture. Many of the works I look at have been moved around for hundreds of years, and their condition is part of their story. Why would you want a Titian to look like an embalmed woman? Where condition is concerned, the best paintings are those that have languished in the spare room of a castle.
Science plays an important part. Before I started restoring paintings I was working as a cabinetmaker in Mexico. A client asked me if I knew how to restore paintings. I didn’t, but I took the piece in question to a local restorer who treated it with such disdain that I immediately decided I could do better. I came back to London and completed my training, including a vital chemistry course, before starting my own company.

The partial removal of discoloured varnish on Van Dyck’s Portrait of a Young Girl, undertaken in Simon Gillespie’s studio, reveals the artist’s original colours beneath
A pocket torch is a restorer’s most important tool. When I started out in this industry, restorers were embarrassed to be seen carrying around a pocket flashlight; now it’s standard practice. The light helps you see through the dirt to areas of overpaint, holes in the canvas and bad joins in the wood. A UV light is also helpful because I can use it to see patches of old restoration and varnishes. These lights are my third eye.
Fluctuating humidity is a painting’s biggest enemy. Some of the most common problems I see result from pictures being hung in bathrooms, kitchens and by front doors, where changes in the air’s moisture content can make wood rapidly grow and contract. This in turn causes paint to crack and flake. Adding a backboard can save a picture’s life by reducing humidity fluctuations within the painting, and protecting it from clumsy handling.
Insect damage is another common problem. Often, a work won’t be cleared to leave the country without a certificate proving that it has been freeze-treated. I pass this knowledge on to my clients every day.
‘When the buyer was in Picasso’s studio, the artist’s coffee mug had dripped from a shelf above. That coffee stain has been part of the picture since day one, so I left it alone’
Sometimes we have to undo the work of others. In the mid-20th century people wanted their pictures to lie perfectly flat. To achieve this, large, flat aluminium tables would be heated up like a giant iron. Then, using wax or rabbit-skin glue, the picture would be squashed flat. They would come out looking like plastic floors. My studio uses techniques that can undo this.
From the 16th century onwards, people were constantly updating works. If someone received a medal, for example, they might request for it to be added on to their lapel in an old portrait. As part of my job, I have to decide whether this ‘historical interference’ should be removed. If it’s an important part of the picture’s story, I tend to leave it.
Sometimes the way to restore something isn't immediately obvious. Once someone brought me a Picasso with a brown stain on it, which gave off a whiff of coffee. I researched the picture’s history and learned that when the original buyer was in Picasso’s studio, the artist’s coffee mug had dripped from a shelf above. That coffee stain has been part of the picture since day one, so I left it alone. But who knows what another restorer may do with it down the line.

Even an apparently irretrievable work, such as this painting by Stanhope Forbes (1857-1947), can sometimes be returned to remarkably good condition. The ‘frosting’ is caused by a bloom within the varnish resulting from the picture having been in a flood
Contemporary works present their own problems. Someone recently brought in a work on canvas by Banksy. White canvas is the worst, because it highlights every speck of dirt. Not to mention that it’s practically suicide to try to replicate a spray-paint finish when repairing rips in machine-made canvas.
In terms of the potential length of a restoration project, the sky's the limit. It’s like going to the doctor and saying you have heart pain. You don’t know what’s in store. The most basic dirt removal costs a few hundred pounds for a small portrait. But if thick varnish needs removing, it can cost five times that. When working with museums, we encase works in environmental chambers using airtight backboards sealed with aluminium tape and non-reflective glass.
We do a great deal of analysis, but sometimes paintings reveal wonderful surprises. Sometimes the process of removing layers of varnish and dirt can be dramatic, and works you thought were unsalvageable can turn out to be in amazing condition.
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Determination can reap rewards. I recently worked on a piece that came to me with what looked like areas of fire damage. I nearly advised the client not to buy it. But he was strong-willed, and his commitment paid off. After painstakingly removing layers of dirt using cotton wool swabs dipped in solvents, we unearthed a near-perfect Tudor portrait.
Our methods of using solvents are much less harmful now than in the past. We can adapt them to sit on the paint’s surface rather then penetrate it. We work with dendrochronologists if wood needs dating — there are very few specialists in the world, and we call on one of them if we need their expertise. We can also analyse paint’s chemical composition to determine which pigments are consistent with the picture’s age.
Gut reaction is crucial. Even in this scientific age, when reattributing a work my first visit is still to a connoisseur.