Dating your photographs and paintings from costume and other visual and physical evidence

Establishing an accurate date-range for a painting or photograph is vital for researchers. A reliable circa date can help to confirm the identity of its subject(s) and indicate the stage of life at which they were portrayed. It narrows down possible candidates, may effectively support a long-standing oral tradition, or - as sometimes happens - disproves a presumed identity, in which case alternative names present themselves. At the very least, it will demonstrate the generation to which a subject belongs.

Photographs, as objects, may be dated to some degree from the process used, their physical characteristics, for example the colour, shape and thickness of the mount and the style and design of the reverse. Where the details of the photographer are given, investigation into his/her operational dates usually proves fruitful.

Even more useful are the visual clues offered by a portrait image. Whereas paintings often depict little background detail, studio photographs present a complete setting with backdrop, furniture and other props, elements which can all be used in the dating process. Different formats and compositions may also suggest a particular time period.

Most important of all visual evidence, however, is the clothing worn by the subjects or sitters in a painting or photograph. A visit to the artist's studio, or in more cases, the photographer's studio, was a special occasion and our ancestors generally wore their best or most fashionable clothing for a portrait sitting since their likeness was to be displayed on the wall or in a family album.

Whilst the fashions of the past 50 years or so probably seem fairly familiar, few of us feel confident about judging accurately more distant styles of dress. Some might recognise clothing as loosely 'Victorian' or 'Edwardian' but to the experienced eye, trained in the evolution of fashion through the ages, fine details such as the shape of a sleeve, or style of a hat are recognisably typical of a more specific time period, for example the late-1860s, or c.1900-1905.

It is usually possible to date the dress worn in a painting or photograph to within 5 or 10 years, depending on the image. Generally women's dress lends itself to closer dating as female fashions changed more rapidly than men's dress; similarly younger subjects are likely to be more fashionably dressed than their more conservative elders.

An accurately dated image supplies important missing links in the visual history of a family. It also offers an important historical context and forms the starting point for further discoveries.