Art Restoration

Written by Caleigh Robinson

Photo By Maxim Kotov on Upsplash

Art restoration requires a tremendous amount of careful and steady handling and an expertise in the science behind all of the solutions needed to restore the art. The first step to restoring a damaged and aged painting is to detach it from the base (what is supporting the it/holding it together). Next, the restorer needs to remove any grime from the surface of the painting and/or base. After the painting is completely clean, the restorer can start fixing the physical damage under the painting after flattening it to return it back to the base or a new base. Now the restorer can repair any damage or coloring loss on top of the painting. Painting/spraying a varnishing coat over the painting after all damage has been fixed marks the end of the restoration process.  

Before the restorer can begin the restoration of the piece they are given, they must undergo a series of observative and experimental tests to find out what methods of preservation will best suite the painting. First and foremost, the restorer visually studies the art piece through a visible-light magnifying glass before touching it to prevent any risk of damage. Once data has been gathered on the type of paint used, amount of varnish discoloring, and other causes of physical damage, the restorer can use black light to find any hidden sections/spots of the paint that was damaged as well. A black light examination can reveal a possible restoration before, paint materials, and other spots where the varnish has damaged the painting (what green shows). Another step before the restoration is researching the artist, the time is was made, and/or the painting itself (if popular enough). Researching the artist and painting can tell the restorer how the piece was painted and specific materials they used for the painting to avoid any misjudged coloring or risky solution-testing.  

Once the restorer has talked to their client about what procedures will best fit their desires (while preserving the artist’s original work), the restorer can start detaching the painting from its bases (unless it is only paper and nothing else). The most common form of old art is on a canvas. A canvas is a strong, coarse cloth made from hemp, flax, cotton, or a similar yarn, used to make items such as sails and tents and as a surface for oil painting. A stretcher is a wooden platform that outlines the boundaries of the painting and holds itself together with other lines of wood or keys (triangular shaped wood to go in the corners of the stretcher). The stretcher is usually unstable, needing new nails, new keys, and sometimes even a brand-new stretcher. Not only that, but dirt and dust accumulate behind the painting as well and can only be cleaned by removing the painting from the stretcher. In most cases, the restorer flips over the painting and removes the nails carefully to not rip the canvas paper, then slowly folds the paper out and away from the stretcher to not tear it as well. From there, the restorer can simply pull the stretcher off the canvas and, using a brush, wipe off any dirt/dust that was hidden behind the painting. Though just removing a stretcher is the common course of action taken to restore a painting, complications are not always avoidable. Every now and then, a painting will be glued on to a base, usually wood. Not only is the glue/wax or tape never adequate in leaving the painting flat on its base, but removing the painting is a much harder process. First the artist must determine what kind of substance is being used to keep the base and painting together; animal glue or wax. Luckily for the restorer, if the artists used wax it is extremely soluble with just hot water and can be pulled off after the water or solution is applied. After the painting is removed, the restorer uses a scalpel to scrape off the remaining wax from the base. If glue was used on the back of the painting, the artist but lightly heat the area and use a solution or water to weaken the substance so that it may carefully be removed from both the painting and base without tear. Before taking any course in restoring the painting, the restore must remove the painting from it base to give it more structure, possibly replace the base, flatten the painting to start restoring, and/or fix any damage under the painting.  

Usually the most surprising aspect to art restoration by a paintings viewers/clients, is that surface grime is at fault for an old paintings faded appeal. Surface grime consists of dirt, dust, and any other products/materials that are considered dirty that have gathered on top of the painting over time. Lying underneath the grime however, is the paintings natural color and vibrancy which is easily assessible through the right solutions and care. The first step to cleaning the painting is to remove the surface grime on top of the painting old varnish. There are several solutions the restorer can use to complete this process, such as distilled water, detergents, soaps, enzymes solutions, and other solutions. The restorer will test these solutions in small areas along the edge of the   painting until a known solutions is best for the entire painting. They then repeat this process for the varnish of which lied underneath the grime and use that solutions to carefully remove the varnish. Both of these procedures are done with loose cotton balls. It is extremely important to add only a light pressure to the painting while removing the grime. A tactic many restorers use is removing the grime off areas of the painting with a specific color with one cotton ball, then redoing it with anything on a different area with the same color. For smaller or important areas of the painting, such as a signature, using a small cotton ball (cue tip) to clean the painting is most adequate. Sometimes the restorer may need to test the solutions on different colors of the painting incase a solution damages a paints color or does not help remove the grime atop the color. Stiff brushes may be neccessary if the surface grime is too thick for cotton to remove. Many paintings use the impasto style of painting, meaning the paint has thick and thin parts showing the brush strokes the artist used. Often the varnish will be stuck in the crevices of the impasto areas of the painting, and the restorer will use a scapel to gently scrape off the varnish and brush it off. With the surface grime and varnish removed, the paintings true colors are apparent and the restorer can work toward repairing the paint.  

With some canvases needing to be restored, the painting will be removed from the base now rather than before removing the grime and varnish. In this case, the restorer will need to apply a paper similar to Washi Kozo paper (renewable branches of mulberry bushes) over the painting in small sections. An adhesive is applied under it to make it temporarily stick to the painting, and then a water adhesive is applied over the paper for the same purpose. After the paper is securely on top of the surface of the painting, the restorer removes the painting from its stretcher by removing the nails along the edges of the wood. If there is lining on the back of the painting, the restorer can easily peel off the lining inch by inch due to the glue being old, dry and brittle. However if the glue is too thick or strong, they can add water or lapanite to the edges of the lining and painting and use a scalpel to scrape off the glue (also how they remove the excess glue from the back of the painting). To a restorers surprise, rarely there will be an inscription underneath the lining made by the artist, usually a date, title, or any other extra information about the painting.  

After the painting color is fully visually restored, the restorer flattens the painting to start repair any physical damage. They make the painting pliable and stable by adding moisture to the painting with a spray while it is on a hot table. Once the proper amount of heat, pressure, and moisture has been applied to the painting, it is placed on top of a cotton (absorbent) thin sheet. The restorer then secures the painting under a thin plastic felt by taping down the edges of felt over the painting to the counter it rests on. A machine of which the painting is resting on, is made to suck in all air and moisture around/in the painting while slowly heating it. This serves a purpose of making the painting completely flat and can last several days.  

Once the painting is completely flattened, the restorer repairs the base for the painting to be returned onto. Sometimes the stretcher will need to be completely renewed, where in that case new wood and keys will be personalized to match the before stretcher for the painting. Otherwise, the restorer can simply clean the wood and keys (often new keys will be used though). The same mothod of cleaning the grime off of the painting is used for cleaning the grime off of the wood of the base. A new tacking edge may need to be used for a stronger support and less tear to the painting’s connection to its base. The best material to do so is belgium linen since it three times a strong as cotton (it is composed of natural flax seeds) and sticks easily to tape. Using the folds and creases on the paiting, the restorer can accurately fold the painting back onto the stretcher evenly and start nailing the painting to the stretcher. The nails are places about an inch or two apart starting from the middle of on edge to the corner of the stretcher.  

An isolation varnish is vital to the restoration of a painting, especially since it will need to be restored again eventually in the future. The isolation varnish serves to place a layer between the painting and any color correction/new paints on top of it. That way the next restorer will have no problem color correcting the painting and everything remains reversible incase any mistakes come up in the restoration process or the client is not pleased. Once the varnish si applied with a brush and evenly distributed across the painting, the restorer can begin fixing any physical damage to the painting. They will start by placing putty in any noticable/deep cracks in the painting. Then any excess putty will be removed with distilled water and a cotton swab (same technique as removing the surface grime of a painting). Sometimes if the painting hs a lot of impasto, he restorer can/will make the putty distribution uneven to match the original paint strokes of the painting. The paint applied to the painting after will have no oils so the paint does not oxidize or change color over time. Finally, the last layer of varnish is applied, sometimes more glossy then not (depending on the paint technique and material).  

Refrences:

http://www.yalescientific.org/2010/12/art-restoration-the-fine-line-between-art-and-science/  

https://journals.openedition.org/ceroart/4924

https://www.icomos.org/en/what-we-do/focus/179-articles-en-francais/ressources/charters-and-standards/166-icomosprinciples-for-the-preservation-and-conservationrestoration-of-wall-paintings

https://fineart-restoration.co.uk/articles-stories/