A collector in Edinburgh once showed me a drawing she had bought thirty years earlier, directly from the artist's studio, for a few hundred pounds. It was a significant work: large, detailed, done in graphite and red chalk on high-quality laid paper. It had spent most of its life in a cardboard tube, loosely rolled, stored in an attic that experienced wide seasonal temperature swings.
The drawing was now foxed throughout (covered in irregular brown spots caused by mold spores feeding on the paper's organic content), yellowed in the areas where the paper had been in contact with the acidic cardboard, and lightly creased from being compressed under other stored items. The artist had since become well known. A comparable drawing sold at auction the previous year for a significant sum. Hers was effectively unsaleable in its current condition and would cost more to restore than it was worth on the open market.
This story is not unusual. Original art is robust enough to survive centuries under the right conditions and fragile enough to be seriously damaged within decades under the wrong ones. The conditions that protect art are not complicated to maintain. They require some attention and a small number of ongoing decisions about how you live with your collection.
The Three Primary Enemies of Art
Light
Light degrades almost every material used in art. Ultraviolet radiation bleaches pigments, yellows paper, fades photographs, and causes organic materials to become brittle. The damage is cumulative and irreversible: there is no way to restore faded color once it has gone. According to conservation standards established by the [American Institute for Conservation (AIC)](https://www.culturalheritage.org/), even low levels of UV exposure accumulate over years into significant deterioration, particularly in works on paper and photographs.
Natural daylight is the most damaging source because sunlight contains high levels of UV radiation and its intensity far exceeds most artificial light sources. Works on paper, photographs, watercolors, works in pastel, and dyed textiles are particularly vulnerable. Oil paintings on canvas are more robust but still susceptible to bleaching and surface changes with prolonged direct light exposure.
Never hang any artwork where it receives direct sunlight. North-facing walls are ideal. For south- or west-facing rooms, UV-filtering window film (available from conservation suppliers) or consistently drawn blinds during peak light hours will help significantly. Position works away from spotlights and track lighting that direct heat as well as light onto the surface.
When framing works on paper and photographs, always use UV-filtering glazing. Conservation glass or acrylic such as Tru Vue Conservation Clear or Museum Glass blocks over 97 percent of UV radiation and is standard in any serious conservation framing. The detailed guide on framing art properly covers glazing options in full.
Humidity and Temperature
Fluctuating humidity is the single greatest risk to most works of art in a domestic environment. Paper, canvas, and wooden supports are hygroscopic, meaning they absorb and release moisture as ambient humidity changes, causing them to expand and contract. Over time, this cyclical movement causes paint layers to crack and flake, paper fibers to weaken, and wooden supports to warp and split.
The ideal relative humidity for most art is between 40 and 55 percent, with temperatures stable and moderate, ideally between 16 and 24 degrees Celsius (60 to 75 Fahrenheit). The key word is stable. A room that maintains a consistent 50 percent humidity is far better for art than one that fluctuates between 30 and 70 percent even if the average is correct. The cyclical stress of the fluctuation is what damages materials, not any single humidity reading.
Rooms to avoid: kitchens and bathrooms, where humidity spikes dramatically with use; attics and basements, which experience extreme seasonal swings; rooms adjacent to exterior walls in climates with harsh winters, where wall temperatures can fall low enough to cause condensation problems. External walls in older buildings with poor insulation are a particular risk.
A domestic hygrometer costing under $30 will tell you the humidity level in any room where you are considering displaying art. A humidifier in dry winter conditions and a dehumidifier in damp summer conditions can maintain the right range in most domestic environments without significant expense.
Pollution and Dust
Urban air pollution deposits sulfur compounds, nitrogen oxides, and particulate matter onto exposed surfaces, yellowing varnishes, attacking metal components, and gradually discoloring paint films. Dust accumulation is similarly damaging over time and attracts moisture and pests as well.
Keep rooms where you display art well ventilated but not in direct airflow from open windows or air conditioning units. Dust picture frames and glazing regularly with a dry, clean cloth. For unglazed paintings and reliefs, do not attempt to dust the painted surface yourself. Surface cleaning of any kind should be done by a professional conservator.
Specific Care by Medium
Oil Paintings on Canvas
Oil paintings are among the most durable forms of art but still require specific care. Canvas is vulnerable to impact damage: even moderate pressure from behind will crack older paint layers. Always handle paintings by their stretcher bars or frame, never by the canvas surface. Avoid hanging paintings on cold exterior walls where temperature differentials can cause condensation on the back of the canvas.
The varnish layer on most oil paintings requires periodic attention. Old varnish yellows significantly over decades and can obscure the original color values of the work. Revarnishing is a conservation procedure that should only be done by a trained conservator. It is not a DIY task and attempting it yourself risks permanently altering the painting's surface.
Works on Paper
Drawings, watercolors, pastels, prints, and photographs on paper are the most sensitive category in most domestic collections. In addition to UV and humidity precautions, works on paper should always be framed with conservation-quality materials: acid-free mat boards, conservation-quality backing boards, and appropriate glazing.
Never use adhesive tape of any kind to attach a work on paper to its mount. Even archival tape causes staining and chemical damage over time. Proper conservation mounting uses hinges made from Japanese tissue and wheat starch paste, both of which are reversible and chemically stable. Most commercial framers do not use these methods unless you specifically request them.
Works on paper not on display should be stored flat in acid-free boxes with interleaving tissue between each work. Rolling is acceptable for very large works that cannot otherwise be stored, but tight rolling causes damage. Roll works on large-diameter tubes of at least four inches in diameter, and store in acid-free wrapping. The Edinburgh drawing described above is the direct consequence of ignoring every one of these precautions.
Photographs
Photographic prints, particularly traditional silver gelatin and color chromogenic prints, are among the most light-sensitive works you can collect. Contemporary pigment inkjet prints (often called giclees) are considerably more stable, but still benefit from UV protection. All photographs should be framed with UV-filtering glazing as a minimum, and stored in acid-free envelopes or archival sleeves in a stable, cool environment. Never store photographs in contact with standard plastic sleeves, rubber bands, or acidic paper envelopes.
Sculpture and Three-Dimensional Works
Sculpture in metal, ceramic, glass, or stone is generally more robust than works on paper or canvas, but still requires attention. Metal sculptures corrode in humid or polluted environments. Bronze in particular develops patina that should be preserved, not cleaned off. Never use household metal cleaners on art-quality bronze. Ceramic and glass works are vulnerable to impact; display them on stable platforms away from high-traffic areas.
Handling Art Safely
Most damage to art in domestic collections happens during handling: moving, hanging, cleaning, or repositioning. A few consistent habits prevent the majority of incidents.
Always use clean, dry hands or white cotton gloves when handling works on paper and photographs. Skin oils and moisture cause staining that becomes permanent over time. Carry paintings vertically, not horizontally. A painting held horizontal with only one hand below the frame is one slip away from falling. Use two people for any painting larger than 60 by 80 centimeters. When setting a painting down, lean it face-in against a padded wall and support the bottom edge with a folded towel to prevent denting the canvas from below.
For hanging, ensure fixings are appropriate for the wall type and the weight of the work. Most hanging accidents are caused by inadequate fixings. A painting falling from a wall damages both the painting and, frequently, whatever is below it.
When to Call a Conservator
Amateur conservation attempts cause some of the worst damage seen by professional conservators. Do not clean painted surfaces with anything, not water, not proprietary cleaners, not dry cloths. Do not try to remove old varnish yourself. Do not attempt to repair tears or losses in canvas or paper. These interventions, done incorrectly, are frequently irreversible and can make a damaged work effectively unsaleable as well as visually compromised.
Call a professional conservator as soon as you notice any active damage: lifting paint, mold growth, insect infestation, or structural cracks in canvas or panel. The [Institute of Conservation (ICON)](https://icon.org.uk/) in the UK and the [American Institute for Conservation (AIC)](https://www.culturalheritage.org/) in the United States both maintain directories of accredited conservators specializing in specific types of work. Using an accredited conservator matters: the field has no formal licensing requirement in most countries, and unqualified practitioners cause significant damage every year.
For the related question of how to protect your investment through appropriate framing and presentation, see framing art: glass, matting, and why it changes everything. For the broader context of what you are protecting and why it matters, how to buy your first piece of original art covers the initial acquisition decisions that make preservation worth thinking about in the first place.
