Framing and caring for a canvas

Many homes have a painting on canvas, perhaps from a relative, a gallery or a local artist. A canvas reacts to damp, dry air, heat and light. Where it hangs, and how it is framed and handled, all make a difference to how it ages.

How a canvas reacts to the air

Museums Galleries Scotland points out that most paintings contain wood, in their stretchers, strainers and frames. All wood can get woodworm.

The National Gallery explains that a canvas takes up moisture from damp air and gives it out into dry air. The canvas moves as it does so. The paint is much less flexible, and it can crack or flake.

Frames and glass

Icon, the Institute of Conservation, says the wood in UK picture frames is often pine. Oak, lime and other woods also appear. Decoration on many nineteenth and early twentieth century frames is a moulded material called composition, applied to the wood.

Museums Galleries Scotland advises museums to fit glass to protect particularly vulnerable, unvarnished paintings. It also warns that a pocket of damp air can form between the paint and the glass, where mould can grow.

Icon warns that taking a picture out of its frame yourself can cause serious damage. It advises asking a conservator first.

Where to hang it

Museums Galleries Scotland suggests hanging paintings on an internal wall, with space for air behind them and away from draughts. It advises against hanging a painting above a radiator or other heat source, because rising hot air carries dirt.

Light damage builds up over time and cannot be reversed. Ultraviolet light does the most harm, and Museums Galleries Scotland suggests UV-absorbing film on windows. It also advises against individual picture lights, which make hot spots on paintings and frames.

The National Gallery keeps its rooms at a relative humidity of 55%, give or take 5%. Museums Galleries Scotland says mould usually grows when relative humidity reaches 65% or above.

Keeping it clean

Museums Galleries Scotland says never to clean the surface of a painting, even to remove dust, because cleaning can remove paint and varnish. It recommends asking a conservator instead.

For a gilded frame, Icon says dusting once a year is enough, with a very soft brush. Each dusting wears the gilding a little.

Handling and storing

Museums Galleries Scotland advises holding a painting by one bottom edge and one side edge. Never carry it by the top of the frame. Keep your hands off the paint and the back of the canvas, and wear close-fitting gloves.

The same guide suggests storing paintings upright, off the floor, and away from windows, doors and radiators.

When to call a conservator

Museums Galleries Scotland recommends a conservator for any painting or frame with mould or woodworm. Signs of woodworm include fine, sawdust-like debris and small holes in the wood. Icon keeps a register of its accredited conservators.

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