Collection: Art mural

What to Look For When Buying

Start with the support. Old canvas is generally finer and more irregular than modern machine woven cloth, and the tacking edges, where the canvas turns over the stretcher, should show original tack holes, aged fibre and paint that stops naturally at the fold. A canvas that has been relined, meaning backed with a second canvas for support, will have lost those edges, and relining is common on older pictures and not in itself a concern. Panels should be examined for splits along the grain, for cradling on the reverse, and for whether the paint surface has followed any movement in the timber. Craquelure, the fine network of cracks in aged paint, should be consistent with the picture's age and follow the structure of the paint rather than sitting on the surface as an applied effect.

Then look at the surface in raking light and, where possible, under ultraviolet. Retouching shows as dark patches against the pale green fluorescence of aged varnish, and its distribution matters: small losses at the edges and along cracks are normal, while overpaint across a face, a signature or a principal passage is a different matter. Yellowed or bloomed varnish is a surface condition rather than damage and can often be improved by a conservator. Frames are frequently later than the pictures in them, which is normal, and a good period frame is a valuable object in its own right. We describe support, restoration and framing in every listing.

Caring for Your Piece

Oils and works on paper need different handling. Oil paintings tolerate normal domestic conditions provided those conditions are stable, so the enemies are swings in humidity, which slacken and tighten canvas, and direct heat, which cracks paint. Do not hang an oil above an open fire or a heating outlet, and do not put anything on the back of the stretcher, including stickers, packing or backing boards fitted without advice. Dust the frame with a soft dry brush and leave the painted surface alone. Never use water, cleaning products, bread, potato or any of the other domestic remedies that circulate, all of which do damage.

Works on paper, including watercolours, prints and drawings, are far more fragile. Light fades them permanently and cumulatively, so they should hang out of direct and reflected sunlight and, ideally, behind ultraviolet filtering glazing. They must be mounted with acid free materials, since acidic board causes the brown staining known as mat burn, and they should never be pressed directly against the glass, where condensation causes the paper to adhere and mould to develop. Check the reverse of a framed work on paper for old backing boards and tape, both of which stain over time and are worth replacing when a work is reframed.

Periods and Categories Worth Knowing

European oil painting of the seventeenth through nineteenth centuries forms the bulk of the antique market, spanning portraiture, landscape, still life and genre scenes, and quality within each category varies enormously with the hand rather than the subject. British watercolour of the late eighteenth and nineteenth centuries is a distinct and serious collecting field, technically demanding and particularly vulnerable to light damage. Nineteenth century prints, including engravings, etchings and lithographs, were produced in editions and should be assessed on impression quality, state and condition of the paper rather than on the image alone. Later portrait and landscape work of the Edwardian period sits at the accessible end of the field and often represents very good painting for the money.