Research & Publication
Maintenance for Art Conservation
Surface of the painting must be checked for any cracks or chips in the paint, and the back of the canvas for fungi and stains. Also, the wood frame is checked for breakage or shakiness. However, as overall evenly-spread thin cracking is a natural characteristic of oil painting, restoration process of filling in the cracks could actually have a negative effect. Therefore, cracking in oil painting must be inspected by a conservation specialist.
Structure of Oil Painting
The basic structure of traditional oil painting consists of stretched canvas on a wooden frame covered with gesso, an absorbent priming coat substrate for painting. After the canvas has been sized and primed, it is ready to be painted. Layers of paint or varnish are applied to obtain the desired color and texture. Many contemporary paintings, however, deviate from this traditional method, which calls for new approaches and interpretations in restorative techniques
Oil paintings appear to have only one or two layers, but actually consist of several. The various layers of oil painting are conveniently grouped into five categories as illustrated below
Linen is usually used as a support. Paper, silk or wood is also used.
B (Glue sizing)
A very thin layer of glue or resin is used to prevent the oil of the paint from penetrating the canvas. It is also used to prevent oxidation from occurring on the coated canvas
C,D (First and second coating of ground)
These layers provide the background for the paint, which also functions as a cushion for any movement in the support.
Paint is applied to create the image.
F (Picture varnish)
A transparent layer is applied over the painting as its final layer.
Aging and Damages in Oil Painting
Aging in an artwork is a normal phenomenon. In oil painting, the canvas ages and loses elasticity and the colors of the paint and varnish fade over time. Oil paintings are sensitive to changes in temperature and humidity, and therefore contract and expand as a reaction. The repetition of contraction and expansion transforms the surface of the painting and causes cracks and peels in the paint, fungal growth, whitening, and other damaging effects. Paintings are often soiled or torn because of careless handling, and sometimes their condition is worsened because of improper restoration. The most severe damages to artwork result from improper handling, wrapping, or accidents that occur during transport. Although shock to the work causes sudden damage, deterioration from vibration is often overlooked because it takes time to manifest. Most physical damages are caused by improper exhibition practices or storage.
The images below demonstrate damages on the painting Standing Girl by Kim Yong Joo
- Before restoration
Restoration Process in Oil Painting
To perform an accurate diagnosis, various technologies are employed to inspect the painting before its restoration. Scientific research methods such as photometry, ultraviolet and infrared photography, X-ray and microscopes are used. Sometimes small amount of specimen is collected and sent to specialists for cross-section research and scientific analysis.
The restoration process differs slightly depending on the condition of the artwork but it is normally carried out as shown below. - Sayang (1927) by Kim Ju Kyung
- 1. Investigetion of artwork before restoration (through photos and documentation) Front side, Back side before restoration
- 2. Cleaning the surface (Dust, yellowed varnish and other pollutants) Cleaning the back side of the canvas/ Back side Before and after the cleaning
- 3. Consolidation of paint layers Consolidating paint layers(Injecting glue/ Consolidation pant layers(Injecting glue, applying Hanji and ironing
- 4. Reinforcement of canvas and frame Flattening the canvas
- 5. Filling in missing parts Before filling / After Filling / After retouching color
- 6. Color Retouching (Varnish, frame, Backing and etc) Front side after treatment(after varnish coating) / Back side after treatment(back protection panel attached)