Acrylic paintings . Acrylic on linen.
Acrylic paintings were introduced in the 1950s and the material differs from oil paint in chemical and physical properties. There are two types of acrylic paints used in acrylic paintings. There is solvent-based and water-based. Solvent-based acrylic paints are soluble in mineral spirits, and water-based acrylic paints are water-soluble. Acrylic paint differs from oil paint in both its quick drying time, and how the paint dries. Acrylic paint dries in as little as thirty minutes, and dries by the evaporation of the solvent or water.
Preventive conservation Acrylic paintings require attentive preventive care. Due to the soft nature of the paint, it attracts and holds dirt and debris, creating difficulty when cleaning and resulting in darkening colors over time. Due to the characteristic of acrylic paint, varnishes will diminish top layers of the paint and affect the colors' vibrancy. Storage of acrylic paintings should be clean and free of dust and heat – below room temperature is best as it will reduce further softening of the top layer of the paint. Exposing acrylic paintings to temperatures ranging near sub zero will cause damaging cracking. Acrylic paint is highly susceptible to mold growth. This is a growing concern for artists and conservators as removal causes some degree of damage to the original paint.
Conservation and restoration methods Preventive care seems to be the best method of conservation. However, after more than 10 years of investigation, conservators are now better able to understand the risks of swelling, extraction, and gloss changes that are associated with surface cleaning treatments. Wet cleaning systems are now being developed that help to minimize the risks associated with cleaning acrylic paints.
Blacklight or fluorescent/luminous paintings Blacklight or
luminous paint is typically made up of fluorescent dyes mixed into paint. These dyes are not a typical dye, but rather a pigment that is suspended in a carrier or resin. This pigment is what gives off a glow when exposed to ultraviolet light. This glow or light is created by the energy that is released from the pigment. While the fluorescent paint layers reflect light, the paint layer darkens over time and decreases in fluorescence.
Preventive conservation The intensity of fluorescent paints can decline quite rapidly, making it difficult for conservators to care for. This is because the brightening agent that is mixed into the paint is not stable. Some fluorescent paintings can only be displayed in the dark with UV-lights. These requirements can make choosing appropriate lighting and exhibition and storage space for preventive conservation challenging. For fluorescent paintings that are displayed in dark rooms with UV lights, it is recommended to have an automatic lighting system.
Preventive conservation Tempera paintings have many of the same problems of condition and conservation as other painting mediums. These include changes in the work due to unstable and fugitive pigments. The aging of a paintings supports and
ground will also impact the paint layer. For example, cracks can form in a gesso ground due to the embrittlement and movement of its support, then become visible in the paint film.
Preventive conservation Like all painting mediums, enamel is subject to damage from improper handling and environmental stressors. Jackson Pollock's
Mural for example was subjected to several moves, likely having been rolled and unrolled each time. These moves may have taken a toll on its condition. The paint flaked, and the original stretcher weakened causing the painting to have a noticeable sag. Another of Jackson Pollock's paintings,
Echo, endured yellowing at the top of the canvas due to strong museum display lights.
Conservation and restoration methods Conservation treatments can take the form of adhering a lining to the canvas with wax-resin to the reverse side, replacing the painting's original stretcher, and varnishing the painting. In Jackson Pollock's
Echo, solvents were used to remove a thin layer of the canvas to even out the work's coloring.
Encaustic Encaustic is a method of painting that involves dry pigments mixed with hot beeswax, then applied to the surface of a support such as wood or canvas. A completed painting is then finished by taking a source of heat to reheat the surface and fuse it together. Encaustic paintings do not require a varnish, are resistant to moisture, and do not yellow. Controlling the light, temperature, and humidity levels can prevent this type of damage from occurring.
Conservation and restoration methods Surface cleaning on encaustic paintings can typically be done with distilled water and swabs is sufficient. For more challenging cleanings, solutions made of beeswax and carbon tetrachloride can be used. One of the biggest challenges in treating encaustic paintings is identifying the different waxes used to determine the appropriate treatments. Infra-red photography and gas chromatography can be used to identify the various types of waxes. Frescos, like most works of cultural heritage, have specific climate parameters for preservation. Humidity and water damage cause mold to develop. The mold
aspergillus versicolor can grow on frescos and consume nutrients effectively causing pigment discoloration and wall detachment from rot.
Preventive conservation Ideally, buildings with frescos would be outfitted with central air with humidity adjusting features to keep the paintings in a cool and dry environment with low humidity. Frescos can be found typically in old churches and other ancient structures such as temples and tombs. These types of structures can be limited with additional means like environmental controls. Deterioration of frescos can be caused by environmental pollutants. These pollutants can be physical, chemical, or biological. The many layers can deteriorate from the materials chemical compositions reacting to pollutants or environmental conditions such as humidity, temperature, light, and pH.
Chemical Degradation – Evident with pigment discoloration, stains, and the presence of biofilm.
Physical Degradation – Evident with cracking of layers.
Lacquer There are a variety of
lacquers that have been, and continue to be used such as Urushi (unprocessed lacquer), Guangqi (processed), Nitrocellulose, lacquers with acrylic resins, and water-based lacquers, but the most well known lacquer is Urushi lacquer.
Preventive conservation While lacquer is a hard material, it is best to first prevent damage and loss by maintaining proper environmental conditions. Lacquer is susceptible to cracks and loose joins from fluctuating temperatures and relative humidity. Extended exposure to light can also cause lacquer to lose its durability. Pastel artworks should be matted and framed. Framing should be under ultraviolet filtering acrylic sheeting.
Watercolor and gouache Water color and
Gouache paintings are pigments mixed into water-soluble gums that are applied onto paper or rigid board supports. Due to its thin washes and light colors, watercolor paintings are very light sensitive. Also, due to their exposed support they are vulnerable to damage from dirt, dust, and pollutants.
Conservation and restoration methods Some treatments to watercolor works may include a washing treatment to remove discoloration from acidic mounts, tapes, and adhesives. Stains from these products can also be treated with solvents. Tears and losses can be repaired with products such as wheat starch paste or methyl cellulose, and weakened paper can be strengthened by attaching a lining.
Scroll and screen paintings Scroll Paintings,
Hanging and
Hand, and screen paintings are made of ink, color, pigment, silk and paper. Scroll paintings often are multiple layers of paper and silk attached to wooden bars called a stave and dowel. Screens are often single panels that are joined by paper hinges that fold into each other like an accordion.
Preventive conservation Scrolls and screens are vulnerable to damage from fluctuations in temperature and humidity. Exposure to light for extended periods of time can cause silk and pigments to fade, and paper to darken. Glazes and films that filter ultraviolet light can help to prevent damage from UV radiation. Creases and abrasions may also form on scroll paintings from repeated rolling and unrolling, squeezing the scroll or tying the cord too tight. Screens can become distorted from uneven tension between the back and front side panels.
Conservation and restoration methods Conservation treatments require significant research as the variations in technique and materials among Asian scroll and screen paintings is great. In general some types of conservation treatments that may be conducted on scroll paintings and screens include remounting, consolidation of pignments, removing old backings, and in-painting and retouching. In-painting and retouching materials for scrolls and screens is not reversible. In-painting and retouches should only be done on losses or fills. Inpainted areas can darken due to losses that have a heavy concentration of animal gelatin/alum for inpainting. == Painting supports and preventive conservation ==