Mission

Know the rogue's gallery.

Briefing

Is it a genuine Old Master or just an old paint-by-number? Take a closer look and find the truth.

General research

First things first, examine the artwork. Begin with an objective study of the physical attributes. Write down what you find. Consider the size of the painting, coloring, and frame. Look for evidence of attribution, such as a signature, studio imprint, copyright or title.

If it's an item that came through family channels, record the known history of the painting: Where it was bought? For how much? And write down any interesting stories about how it was acquired.

Next, if you're lucky enough to have a piece with an attribution, take the name to a local library or do a search online. If you're really lucky, you may find information on auctions or sales of that artist's work. You may also want to take the image (or a good copy) to a public or university library. Ask the librarian for resources and reference works that could help you learn more. For example, if the piece includes a signature or initials, ask to see a dictionary of artist signatures.

You will probably need the help of an expert to investigate paintings and prints. Scientific testing may also be advisable. Authentication efforts should not be expected to prove a work is by a particular artist, but to disprove it.

Evidence and expert opinion may be in conflict. If this happens, you may want a second opinion or additional tests. In the final analysis, you may have to rely on your own judgment.

History Detectives Tips

• Use a magnifying glass or jeweler's loupe to look for small details, such as fresh paint in the cracks of paintings.

• Use UV or "black" light to look for signs of painting repair or alterations. An overall green glow may signal the use of a masking varnish.

• Watch out for paper, new or old, glued over the back of a painting. It may hide condition problems, inconsistencies, or manipulations.

• Beware chromolithographs masquerading as oil paintings. The chromolithograph process made art available to the middle class in the 19th century. The technique uses layers of color and its richness can fool the eye of the uninitiated.

• Think it's the painting of a famous artist? See if there's a catalogue raisonné for the official listing of all the artist's works, the medium they were created in and the history-or provenance-of ownership.

Image source: The battle of Gettysburg, Edwin Forbes, Library of Congress Prints and Photographs Division