Restoration of paintings and works of art

Treatment of an overly glossy, opaque varnish, and of a yellowing varnish. The varnish veiled the whole in a bluish grey and had made the bouquet of roses in her hand disappear, along with the foliage and the flowers on the ground.

After solubility tests, the varnish is reduced area by area: the flesh tones, the blues of the dress and the roses recover their value, with no overpainting whatsoever. The excessive gloss is brought back to a just saturation, the one the work had to begin with.

Treatment of an opaque, blanched varnish — blanching —, in the presence of damp. Damp had penetrated the varnish and turned it white. The milky veil was such that the work could not be read at all: the face could barely be made out, and the hair and the mouth had lost all colour.

The blanching is treated first, then the varnish reduced by degrees. The flesh tones, the golds of the hair, the red of the mouth and the browns of the background recover their original colours.

The network of cracks, however, remains: it belongs to the age of the work and is not removed.

Treatment of the varnish and of a network of craquelure. An oxidised varnish covered the work with a bluish veil; beneath that veil, a network of cracks ran across the whole surface — the face, the chemise, the bodice.

Consolidation comes before any cleaning: as long as a flake moves, nothing else can be undertaken. The cracks are treated one after another, and the varnish is then reduced in stages, after solubility tests.

The work recovers its values: the modelling of the face and the gaze, the brown of the hair, the red of the coral necklace and the embroidery of the bodice.

Reduction and treatment of the varnish on a canvas. Each operation is carried out separately, and in this order: dusting of the surface, then removal of the surface dirt, then treatment of the weakened support, and and last of all the reduction of the varnish. Carrying out two of these operations at once would mean working on an unstable layer, and making the varnish answer for what belongs to the dirt — or the other way round.

Cleaning the varnish of a painting — or rather reducing it — must be done with great care and by a professional alone, to avoid over-cleaning and irreversible damage. Solubility tests are needed to establish which products are suitable.

The varnish of a painting can be kept if it is of good quality. Regenerating a varnish is possible. Cleaning the surface of the painting is sometimes enough.

Every painting calls for different products, according to the chemical, physical and mechanical make-up of the work itself. The skill of a Maître Artisan in the restoration of paintings lies in defining the right method and in matching precise gestures to appropriate materials.

Treatment of old overpaint and earlier restorations, and reduction of a yellowed varnish. As it aged, the varnish had turned brown and closed the work up: the sky was going brown, the water no longer returned the light, and the figures on the bridge and in the boat were disappearing into the dark mass.

The overpaint and earlier restorations, laid over the paint layer through the years, are identified and then removed: once taken down, they let the original material reappear, and it is reintegrated only where it is genuinely missing.

The varnish is then reduced in stages, after solubility tests, and never down to the paint layer. The work recovers its light: the trail of the sun on the water, the mills in the haze, the red ensign and the crew's clothing — everything the painting still held beneath the varnish.

Icon painted in oil on panel, depicting Saint John slaying the dragon. It belongs to the first register, above the doors of the iconostasis in the church of Saint-Julien-le-Pauvre, in Paris.

It carried an extremely thick, resinous varnish that had no business being there. Removing that depth of varnish and its runs took several days of work. The work is shown before and after treatment: the gold ground reappears.

This work is a reproduction of a painting by Raphael. Reproduced by Daoud Corm, Lebanese painter of the 19^th century, it shows the quality of its execution and points to the influence of the Italian school, acquired during his training at the Accademia di San Luca in Rome, under the painter Roberto Bompiani.

Treatment of the craquelure on an oil on canvas. Craquelure in an oil on canvas is often a sign of the ageing of the varnish or of the paint layer, of a weakened ground — or of the absence of any ground — or again of a fragile support, whether through its own make-up or through knocks it has suffered.

Treating craquelure in a painting calls first for understanding where the cracks came from, and then for choosing the least invasive steps.

When a painting shows widespread flaking of the paint layer, consolidation becomes necessary: either by local injection, or across the whole surface, or from the reverse, or both.

Treatment of oxidised pigments and old overpaint, on a painting on copper. The work represents the Annunciation to the Virgin Mary; the detail shows the angel holding the lily.

The paint had lifted and cracked, and the old overpaint, as it aged, had become visible: it read as dark patches over the original material.

The overpaint was removed first, then the oxidation treated — on copper, the paint layer and the metal do not age at the same rate, and it is the support that sets the terms.

The losses were finally reintegrated with illusionistic retouching: the dove, the ray of gold, the flesh tones and the drapery recover their legibility, with nothing added to the work.

A large modern painting, by Louise Barbu. The canvas showed tidelines, stains and assorted scratches. On a painting as smooth as this, where one tone passes into the next without a break, the slightest tideline is visible from the far end of the room.

The treatment is carried out area by area, from the gentlest measure to the most committed, with tests beforehand: on these modern paints, thin and barely covering, over-cleaning would leave a mark more visible than the stain.

The scratches are then filled level with the surrounding surface and reintegrated. The gradations recover their continuity, and the background its unity.

Damp stains and a tear in the paper, following water damage. Water had migrated into the sheet: tidelines, foxing and a greyish veil over the blue ground and the flesh tones, and paper weakened to the point of tearing, here at the shoulder.

A pastel is not treated like a painting: nothing holds the colour in place. It rests on the grain of the paper alone, and the slightest contact takes it away. The whole treatment is therefore carried out without ever touching the surface — the work is done from the reverse, the sheet laid flat, the gesture guided with tweezers under the binocular microscope.

The tear is closed from the reverse, fibre by fibre. The stains are drawn out gradually, by indirect contact and controlled drying, without ever wetting the coloured surface.

A pastel is never fixed. A fixative would make the surface more stable, but it would extinguish the velvety bloom that is the whole point of the technique — precisely what the artist was after. The background recovers its blue, the skin its light, and the work keeps its powder.

A large painting, saved from a fire. Soot and blackening had covered the entire surface: the faces, the fabrics, the background — nothing could be read any longer. A long tear crossed the canvas.

The tear is consolidated first and the canvas re-tensioned: no cleaning is undertaken while the support is unstable.

Next comes the reduction of the soot, carried out area by area and in stages. The detail in the roundel shows what the paint layer had kept beneath the deposit: the face recovers its modelling, its flesh tones and its gaze.

The right-hand view was taken during treatment, not at the end of the work.

Treatment of the flaking paint and reintegration of the colours. On a contemporary work by Bilal, the paint layer had lifted in places: flakes stood proud of the surface, ready to fall. They are consolidated one by one before anything else is done — as long as a flake moves, nothing else can be undertaken.

Then comes the reintegration of the colours, in illusionistic technique: the retouching must disappear to the naked eye and be legible only under the magnifier or in raking light. On this kind of painting the exercise is formidable — broad flat areas, a red with no variation to hide in, and a granular surface whose texture must be matched as closely as its colour.

The materials used are reversible: the treatment can be removed without touching the original.

A torn painting calls for knowledge of the quality and the reactivity of the support, as well as the reactivity of all the components, in order to establish the right method of treatment and the appropriate materials.

Restoring a torn painting calls first for protecting the paint layer, so that the weakened areas are preserved while the work is carried out.

Lining a painting remains the last available solution, and only if the canvas has become very fragile over the whole or a large part of the work.

A painting damaged by a tear can be treated by consolidation from the reverse, with a non-woven patch or by the thread-by-thread technique.

Consolidation, lining, retouching and varnishing. Lining remains the last available solution, and only if the canvas has become very fragile across the whole or a large part of the painting — as it had here.

The paint layer is protected first: this is the state shown above, the surface entirely covered with a facing paper that holds the material in place throughout the treatment.

The canvas is then consolidated at the back with a new canvas and re-tensioned. The losses are filled and reintegrated, and the varnish comes last — the still life recovers its greys, the red of the crab and the pearl of the fish.

Treatment of distortions in a painting: dents and flaring corners. A canvas is sometimes poorly tensioned, or shows dents, and this spoils the look of the work.

It is often necessary to flatten the canvas — and therefore to take it off its stretcher, where that is possible — when the deformations are very pronounced.

This stage calls for great vigilance, and for a protective facing to be applied over the whole paint layer before anything is done.

Reintegration of the arm of Christ on the plaster sculpture of Michelangelo's Pietà (a copy) in the church of Saint-Antoine, Paris 12th^e.

At the heart of the church of Saint-Antoine stands a copy of Michelangelo's Pietà. The arm of Christ, broken into pieces — twenty-four fragments, with losses — was reassembled and set back into the work.

Restoring the sculpture required the removal of old adhesions and a reworking of the fixing, taking account of the weight of the arm and of the support.

A decoration painted on glass, on the scale of a shopfront. The glass panel of a former Paris bakery and patisserie, painted on glass, was broken over its whole height.

This is neither a painting nor a frame: it is a monumental decorative scheme, belonging to the building as much as to the history of the neighbourhood. The support lays down the law — glass cannot be filled or stopped like a canvas, and the painting is read from the other side.

After consolidation and reintegration of the painted decoration, the paint was mounted on new glass, and the panel was then set back in place on the shopfront — gilding, foliage, landscape and garlands of flowers all returned to legibility.

L’Espiègle, terracotta bust of Jean-Baptiste Carpeauxwhich reached the studio in several fragments, the head separated from the base.

Reassembly, rejoining, filling of losses and harmonising of tone: the work recovers its legibility as a whole.

The work was broken. It arrived in pieces: the base separated, the gilded cloud detached, and several fragments loose. Everything had to be laid out, the parts assembled, and the missing elements then reintegrated — nothing is remade for as long as the original survives.

The timber was moreover riddled with woodworm tunnels. They were treated, the timber consolidated, and the tunnels made invisible.

The losses are then filled and brought level with the surrounding material — this is the state shown in the third view, deliberately left white.

Reintegration comes last: gilding and polychromy are taken up tone by tone, kept slightly below the original, until the eye travels across the whole figure without catching.

A water carrier in patinated plaster, its pitcher broken into several fragments: consolidation, assembly of the parts, filling, illusionistic retouching and an isolating layer.

Lion after Antoine-Louis Barye. The work had been broken in the past and already treated by someone else: the fragments had been stuck back, but the joins were overflowing with filler, and overpaint covered the patina far beyond the losses. The break could be read from one end of the flank to the other.

First it had to be undone. The old adhesions are taken down and the fills and overpaint removed — after testing, with solvents chosen for each material encountered. This is the most delicate stage of the whole treatment: one never knows what an old product has done beneath the surface, and it has to be discovered without taking the original away with it.

The elements are then reassembled along their line of break, the fills remade and brought level, and the colour and patina then reintegrated. The work recovers its original legibility: the modelling of the muscles, the movement of the mane, and the contrast between the bronze of the coat and the dark green of the base.

Working after an earlier restoration is often more difficult than working on an untouched piece. This is where the demands of the craft lie: knowing the materials, their reactivity and their compatibility, and using only products that are appropriate, stable, identifiable — and reversible, so that whoever works on the piece after us can undo what we have done.

Marble sculpture by Edme Marie Cadoux, damaged during a house move. A chip of the drapery had broken away, and the surface, darkened by numerous stains and soiling, had lost the whiteness of the stone — down to spatters of paint.

The fragment is bonded back along the line of the break, with a reversible adhesive, after a dry fitting: the two faces of a break fit together in one way only, and it is that position which must be found before anything sets. The join is then filled and retouched to the tone of the stone.

Marble is a porous stone: a stain does not stay on the surface, it migrates into the mass of the stone. It is therefore not scrubbed away but drawn out. After testing, cleaning is carried out with poultices, which slowly absorb what has penetrated, area by area — with no running water, and no acidic product, which would eat into the polish and leave a matt halo.

With the soiling gone, the stone recovers its grain and its light: the deep whites of the body, the veil of the drapery, and the translucency the sculptor had gone looking for in the thickness of the block.

Faience plate fractured across the rim, with losses of glaze. Rejoining the fragments, filling and retouching give the decoration back its continuity: the break disappears from the reading.

A flower-shaped dish, which arrived with many petals broken, losses and a dulled glaze: the fragments were rejoined, the missing parts made good, and the retouching and glaze then taken up again.

Carved ivory group. The work arrived with one of the animal's legs broken and the leafy branch it holds in its mouth detached, laid beside it in several pieces.

Each fragment is repositioned and secured along its original break: nothing is remade for as long as the original survives.

The losses are filled and toned to match the colour of the old ivory.

The lid of an ivory powder box, broken in two and missing its knop. Once the fragments were secured, the missing material was made good, toned and varnished until the break disappeared from view.

Vinyl figure by KAWS, whose real name is Brian Donnelly, an American artist born in 1974 in Jersey City. Coming from graffiti and skateboarding, he worked as an animator on animated series produced for Disney — One Hundred and One Dalmatians, Daria, Doug — and stands for a popular art, within everyone's reach.

His figure Companion, opened to reveal its organs, is a nod to Mickey Mouse as much as to the artists who opened bodies in order to study them, from antiquity to Leonardo. Still at work today, he continues to produce these editions, which are much sought after.

Dimensions: 26 cm high × 12.7 cm wide × 7.6 cm deep.

This Companion set me thinking about restoration non-invasive and lasting. The broken arm was articulated: rejoining it was not enough, its movement had to be given back. Quite a story. After several days of research and trials, I found the way.

The solution always comes when you take the object's side: the work must not show, and it must give the piece back all its original qualities.

Portrait on canvas of the 18^th century, showing losses and the traces of an earlier restoration. Retouching, resins and fillers had been laid over the paint layer; with time they had discoloured and read more strongly than the work itself.

Removing these earlier restorations comes first. It calls for distinguishing, under the magnifier, what belongs to the original from what has been added to it: only the addition is taken away, never the painter's own material.

The losses are then filled level with the surrounding surface and the colours reintegrated — the flesh tones, the hair, the ruff and the background recover their continuity, with nothing repainted beyond the loss itself.

Filling of the losses and renewal of the varnish. Losses in the paint layer left the white ground showing on the cheek, the neck and the background.

Each loss is filled level with the surrounding paint, then reintegrated in watercolour with a fine brush, tone by tone and slightly below the original: the retouching is legible under the magnifier, never to the naked eye. The varnish is then regenerated to give the modelling back its depth.

A scratch across the neck and the shoulder. It had not merely scratched the varnish: it had taken away the paint layer and even the white ground. It was this ground, laid bare, that read as a pale line from one side of the neckline to the other — the eye caught on it before it even saw the face.

The treatment follows the order of the layers: consolidation of the edges of the loss, then a fill brought exactly level with the surrounding surface — neither hollow nor proud, for a badly judged thickness betrays itself in raking light long before the colour is noticed. Retouching comes only afterwards.

It is carried out with a fine brush, in delicate hatching, within the loss alone. The difficulty is not the colour: it is the network of age cracks running across the whole of the flesh. A smooth retouch, however perfectly matched, would read as a new mark in the middle of an old skin; the pattern of the craquelure must therefore be carried across the fill so that the eye reads the surface as continuous again.

The materials used are reversible and the retouching stops at the edge of the loss: to the naked eye the scratch has gone; under raking light and ultraviolet it remains identifiable. That is as it should be — a restoration is meant to be legible, not hidden from anyone who knows how to look.

A split icon depicting a calendar of saints. The panel was crossed by a long split running its whole length. It first had to be consolidated on either side: as long as the support is unstable, no work on the paint has any meaning.

The work is painted in tempera, with pigments bound in egg yolk and sometimes egg white. The technique grows fragile with age, and parts of the paint layer had been lost. Consolidation is carried out with reversible adhesives and products, the losses are then filled, and the colours reintegrated across the whole of the work.

The retouching calls for extremely fine brushes, and sometimes for a needle. That is the price at which the figures, the finely worked heads and the precision of the faces recover their legibility, exactly as before.

Consolidation of the cracks and reintegration of the colours. The support of the ceiling had moved: a network of cracks ran right across the sky, and into the foliage and the ornament around it.

The cracks are first consolidated and filled — this is the state shown on the left, the fills deliberately left white and visible. The colour is then reintegrated crack by crack, from the scaffolding, following the modelling of the sky and the passage of the clouds.

A work of this scale does not leave its setting: the studio travels to it. Every retouch must read correctly six metres below and at thirty centimetres alike.

The two photographs were taken under different lighting; their balance has been harmonised so that only the difference of condition can be read.

The missing parts are made good in a material compatible with terracotta, then brought level with the surrounding surface. The photograph on the left shows the intermediate state, deliberately left visible.

The child's hand had disappeared entirely. It was recreated from nothing — modelled, fitted to the position of the arm and to the gesture holding the bouquet — and the many losses in the garment and the base were filled.

The reintegration of colour comes last: it does not seek to imitate. It keeps the new work slightly below the original, so that the eye travels without interruption while the intervention can still be told apart at close range.

The four photographs were taken at different moments of the treatment and under different lighting; their balance has been harmonised to the same terracotta orange, so that only the difference of condition can be read.

Reintegration of the mouldings and the gilding. A painting is often framed, and the frame frequently needs treatment of its own. It may have been damaged by woodworm or fungal growth, or have lost ornaments and lengths of moulding — acanthus leaves, shells, bead-and-reel, medallions, ovolos — which are then recreated, fitted, secured, assembled and consolidated.

A frame can be regilded with gold leaf, with copper leaf or with imitation gold, then patinated according to the owner's wishes.

Creating the missing elements from nothing. The cow had no horns: they had disappeared. They therefore had to be made — modelled, fitted to the join and to the line of the head, then brought level with the surrounding surface. When the original no longer exists, this is the only possible course.

Painted contemporary sculpture. The knocks had also taken away the colour layer in patches: on flat, clean-edged areas of colour there is no texture to hide behind — an approximate retouch is seen at once.

The tones are built up on the palette until the match is exact, then laid with a fine brush within the area of loss alone, never straying onto the original paint.

Gilding of the twelve consecration crosses with gold leaf. The crosses are carried by the pillars of the church of Saint-Antoine-des-Quinze-Vingts, in the 12th^e arrondissement of Paris. Time and successive cleanings had dulled the gold and worn the outline: the cross was guessed at rather than read.

Each cross is treated in situ, in the order of the rite: cleaning and consolidation of the support, reworking of the outline and the interlace, laying of the size, then gilding with gold leaf, leaf after leaf, and finally patination to bring the new brightness into accord with the old stone.

The gold here is not an ornament: it is what makes the cross visible from the nave, and what sets it apart from the stone that carries it. Once gilded, the twelve crosses answer one another from pillar to pillar and close the space of the church — which is precisely their purpose.

Gilding with gold leaf. The missing ornaments — acanthus leaves, shells, bead-and-reel, ovolos — are taken by impression, fitted, rubbed down, sealed, then gilded with oil size before being patinated to bring them into chromatic unity with the old gilding that survives.

Gold leaf, copper leaf or imitation gold are chosen according to the work and to the owner's wishes. The final patination is what keeps a repair from showing: new gold left unpatinated always betrays the intervention.

A painting deteriorates first of all through the place where it is kept. Damp finds its way in — a cold wall, a cellar, an attic, a room that is never aired — and a few weeks are enough for growth to become exponential. On this seascape, micro-organisms had formed a scatter of black specks across the whole of the sky and the sea, where the paint is smoothest.

The species involved are beyond counting: some 155,000 species of fungi have been described to date, out of an estimated total of 2.5 million. On historical wall paintings alone, a 2022 study recorded 260 species, belonging to 173 genera. Each feeds on whatever it finds: the glue of the ground, the binder of the paint layer, the varnish, or simply the dust settled on the surface.

The stain is never treated on its own: the whole work is treated. For a canvas, that means the reverse and the stretcher as much as the face, the ground, the paint layer and the varnish — and sometimes its removal. If the work is framed, the frame and the glazing are treated with it: to leave the wood or the reverse contaminated is to guarantee that it all begins again.

These are remedial care, carried out at the studio. They stop where preventive conservation begins, and that belongs to the owner: keeping the work away from cold walls, airing the room, avoiding sharp swings in humidity. A work that is treated and then returned to the same place will be contaminated again.

Conservation and restoration in situ of a monumental painting. A work of this scale does not leave its setting: it is the studio that travels to it, scaffolding included.

The work begins with study. A detailed condition report; examination of the paint layer in raking light and under ultraviolet — which reveals old retouching and successive varnish campaigns — and then pigment analysis: it is this preliminary reading that determines the products, the dilutions and the order of operations.

The canvas bore tears, as well as numerous stains, scratches and tidelines. The tears were brought back edge to edge and consolidated from the reverse; the stains and tidelines treated in stages, after solubility tests; the flaking paint consolidated, the losses filled, and the colour then reintegrated with a fine brush, tone by tone, in keeping with the light of the chapel.

On surfaces of this size, the difficulty is not the gesture but the scale: every retouch must read correctly at three metres and at thirty centimetres alike. One works very close up on an image that will never be looked at closely.

The work concludes with the delivery of the restoration dossier: the initial condition report, examinations and analyses, treatments carried out, materials used and their reversibility, and photographic documentation before, during and after.

Work on the complete set of icons at the church of Saint-Julien-le-Pauvre, one of the oldest churches in Paris.

The restoration of the complete set of works belonging to the iconostasis of Saint-Julien-le-Pauvre was carried out at the studio, after the works had been taken down in situ.

The condition report on the whole set of works, together with the investigations — X-radiography in particular — brought to light earlier paintings beneath the visible paint layer.

The portraits of Saint Thomas and Saint James the Greater, which had been stolen, were painted following exactly the technique and palette of Daoud Corm, the Lebanese painter of the nineteenth^e century, who worked on the making of these icons.

The work was carried out in two campaigns. The first covered the lower register — the scenes from the Old Testament — together with the tondi and the figure of Christ. The second, carried out later, was devoted to the upper register, that of the apostles. The studio treated every work in the iconostasis.

The whole of the work was recorded and published in the book devoted to the iconostasis of Saint-Julien-le-Pauvre. The commission closed with a lecture, given on site, at which each treatment was presented to the public — it is that moment which the first photograph shows.