Living with a painting: light, humidity and placement

A painting in a house is in a worse environment than a painting in a museum, and there is no way around that. Museums hold light, temperature and humidity within narrow bands because damage accumulates quietly and cannot be undone afterwards. A private collector cannot run a gallery climate system and does not need to. What matters at home is avoiding the handful of conditions that do real and permanent harm.

The first rule is stability. A wall that swings between hot and cold, or dry and damp, does more damage than a wall sitting permanently at the wrong end of a range. Wood panels, stretchers and canvas all move with moisture while paint layers move less, so repeated cycling cracks the surface. Pick the calmest wall in the room rather than the one with the best sightline.

Light is the damage you cannot reverse

Fading is cumulative and permanent. Ultraviolet light does the most harm and visible light does plenty on its own, which is why a work hung opposite a bright window will change even behind filtering glass. Paper, watercolour, textile and photographic works are the most sensitive of all. Oil on canvas is tougher, though varnish yellows and some pigments shift regardless of what you do.

Direct sunlight is the condition to eliminate first. That means no wall receiving a moving patch of sun at any hour or in any season, which is easy to misjudge in a room you only use after dark. Watch the room across a full day before committing to a position. Curtains, blinds and ultraviolet filtering film on the window all help, and none of them help if the painting sits in the beam.

Humidity is the second variable and the one people ignore. The usual conservation target sits near fifty percent relative humidity with a tolerance of a few points either side, and the tolerance matters more than the number. Very dry air shrinks wood and paper and lifts paint, while damp air swells supports and invites mould. A cheap hygrometer on the wall beside the work tells you more than any amount of guessing.

• 1
  Never hang work above a radiator, a fireplace in use, a stove or a heating vent
• 2
  Keep paintings off exterior walls in cold climates, where condensation forms behind the canvas
• 3
  Leave a gap behind the frame so air can move, using small bumpers at the lower corners
• 4
  Bathrooms and unheated basements are the two worst rooms in almost any house
• 5
  Hang from two points into fixings rated well above the actual weight of the work
• 6
  Rotate light sensitive pieces on and off the wall rather than displaying them permanently

The rotation habit is the most useful item on that list by a wide margin. Museums limit how long a sensitive sheet spends on display each year and then rest it in the dark, and a collector can do the same with a drawer and a calendar. Two works swapped every six months both survive longer than one work left up for a decade. Nothing else buys that much time for so little effort.

Handling, cleaning and the yearly check

Move a painting with two hands on the sides of the frame, never by the top edge and never by the stretcher bar. Clear the floor and the wall before you lift, and take the wire and rings off the hook rather than sliding the work along the wall. For cleaning, a soft dry brush over the frame is the limit of what an owner should attempt. Everything beyond that, damp cloths included, belongs to a conservator.

Almost every condition problem a private collector meets is slow, cheap to prevent and expensive to repair. The wall you choose on the first day decides most of it.

Look at each work properly twice a year, in daylight, taken down off the wall. You are checking for new cracks, lifting paint, slack canvas, foxing on paper and any brown staining that has appeared since the last look. Photograph anything that has changed and date the photograph. Problems caught within a year cost a fraction of problems caught within ten.