ART RESTORATION

Support Damage

Torn, brittle or otherwise damaged canvases can be restored. The information below deals with removal of old linings and modern methods of canvas repair.

---

 LININGS and OLD LINING REMOVAL

Previous restoration campaigns such as lining, patching, inpainting, etc...  have a useful life but need to be replaced when they begin to fail or discolor. Advances in painting conservation have made some techniques obsolete:  for example - paste linings, some wax linings, linings on aluminum (which are especially bad.) In most cases, the old restoration can be removed or at least improved. Below are examples of how these situations are handled.

---

FACING

Facing is a way of temporarily protecting the paint layers during treatment. The pictures below demonstrate the application and eventual removal of the facing tissue.  Here the painting is being faced. The last photo demonstrates the removal of the facing tissue after the old lining has been removed. Facing is also useful to stabilize tears and paint damage.

 

---

GLUE LINING REMOVAL  Glue linings, or, paste linings, have their origins in the 17th century and continue on a limited scale today. The glue is generally composed of hide glue, Venice turpentine, flour, and a disinfectant. After the glue is applied the painting is left to dry under aThe main problem with this type of lining is the water content of the glue. The moisture can; loosen the ground, cause paint cracking, flaking, and mould. Fluctuations in temperature and humidity can also cause a great deal of harmful expansion and contraction in the years following lining.

Glue lining before removal. Removal of the lining canvas. Notice in the second picture the margins have been trimmed off.

 

Here the lining canvas is removed in thin strips. The old adhesive in then removed with a knife.
 

---

 

WAX LINING REMOVAL
Wax lining methods were developed sometimes in the 18th century. The method is sill being used. Wax linings do not have the moisture issues that glue lining have. They do however permanently darken the One of the advantages it has over glue linings can be reversed by removing the lining canvas and then drawing out the wax adhesive from the canvas using heat and solvents. Here is an example of a wax lining being removed. The lining canvas has been attached directly to the painting canvas. The wax adhesive was unevenly applied resulting in bulges, distortion of the painting canvas, and spot delimitations. Modern lining methods use an interleaf . An interleaf is a layer of fabric placed between the painting and the rigid support. In photo #2 the painting was lined using an aluminum rigid support. Linings on aluminum generally develop problems and should be avoided.

 This is an example of a wax lining onto an aluminum rigid support. This is generally a bad system because aluminum rapidly conducts temperature changes.

 

Here a painting is being lined with wax. The previous wax lining was removed and now the painting is being re-lining with a fresh wax lining.

---

INTERLEAF

Here a monofilament fabric interleaf has been applied to a painting that has had the previous old lining removed. Next a Mylar rigid support will be attached. Notice the center of the canvas is more discolored and damaged that the edges that were shielded by the stretcher bars. (A good argument for backing boards.)

In many cases the margins of a painting are trimmed off the painting to save steps in the lining process. This is never a good idea. Pictured below is a typical finish to the edges of an old glue lining. The margins were trimmed off and a paper tape was used to finish the edges. Picture #3 shows the corner after lining.  Here the interleaf provides a tacking margin.

Here the margins of the painting have been preserved during the lining process. Because the monofilament interleaf is so uniform, strong, and thin, the margins can be relaxed without splitting. Something that is extremely difficult to achieve with other materials.

---

EDGE LINING

Failing margins can be strengthened by tacking on a strip of fabric called edge lining. The painting can then be put back on the stretcher and an even canvas tension achieved. Edge linings are good if the canvas is generally strong. Edge lining is also less invasive than lining.

An edge lining in progress.

---

BEVA LINING

BEVA 371 is an adhesive used to consolidate and line paintings. It comes in a liquid form, and a film form. Here a painting is being lined with BEVA 371 using a vacuum hot table. BEVA treatments can be reversed using heat and mild solvent

Torn or weak canvases can be supported by lining. Here is a set of photos that document a few of the stages of a BEVA lining.

 

---

Before and after treatment.

CLEAR LINING
Lining onto clear rigid supports allow viewing of  stamps, markings, inscriptions etc...

Here is an example of a painting with a makers stamp that was lined onto a Mylar support.

---

TEARS, RIPS, AND PUNCTURES

Tears are mended by consolidating the paint and canvas around the tear, then by fitting the tear together and flattening the canvas back into plane. Large tears usually require lining.

Areas before and after treatment.

 

A tear in the canvas is mended.

---

GRAFTING
Missing pieces of canvas can be restored.

 

 

Before and after mending the canvas. Photo #2 shows voids filled with canvas of a like texture.

   

Here is an example of an old canvas plug. It is important to choose a fabric of like texture and align the weave of the plug with the original canvas. Photo #2 depicts the restoration of a void in the canvas with a like piece of linen.

---

PATCHES

Patches are used to mend small tears in a canvas support.  Below are examples of a wax adhesive patch and a paper and glue patch. It is amazing sometimes to see what has been used to patch tears. Improvised patches and even some done with care can over time can distort the canvas and cause a bulge that can be seen from the front of the painting.

Examples of different old patches.

MODERN PATCHES

A modern patch is made from a piece of sheer monofilament fabric and BEVA film. Because the patch is so thin and evenly attached chances of the patch

---

HOT TABLES


VAPOR TREATMENTS  

Sometimes a canvas has been rolled up or a tear has been left untreated and the edges have curled. To keep from damaging the canvas and the paint layers, it is necessary to gently relax the canvas using moisture.

   

Here the temperature and humidity were elevated in a controlled manner in order to relax this painting that had been rolled up.

Here is an example of how a torn canvas can shrink and curl. Water vapor was used to relax the curls back in plane in preparation for lining. Notice how the gap in the tear has widend due to the canvas shrinking.

---

 

Severe Distortions or DUTCH STRAINER METHOD OF RELAXING CANVAS DISTORTIONS.

Paintings that have severe canvas distortions sometimes need to be treated under tension. The painting below could not be restored properly until the distortions in the canvas were flattened. The painting was stretched in the manner pictured below (called a Dutch strainer), and then slowly relaxed with moisture and tension back into plane. Using a Dutch Strainer each strip can be individually adjusted. It also allows the reverse to lay flat for easier treatment.

Painting attached to a "Dutch Strainer"

Painting before treatment.

LOW PRESSURE SUCTION TABLE TECHNIQUES

The low pressure suction table is different from a vacuum hot table in that it creates a downward pressure through thousands of tiny holes in the tables' surface. This difference makes the low pressure suction table perfect for consolidating flaking paint, relaxing distortions in canvas and low pressure linings of very fragile paintings.

 

 
 
 

VACUUM TREATMENTS

Badly flaking paintings can be effectively treated with a low pressure suction table. Adhesive is applied to the flaking paint and is drawn into the canvas by the air flow through the holes in the table. A tacking iron or silicone spatula can be used to gently relax the paint back into plane. Then a silicone coated membrane can be used to cover the painting and heated under vacuum pressure to set the adhesive. Below a hole in the membrane allows the treated painting to cool.