Numerous works of art are offered for sale with fake or questionable signatures or attributions at online auction sites like eBay. Problem art can also be found at fixed-price "gallery" websites and bricks-and-mortar establishments, but nowhere is it more pervasive than at online auctions. In order to fool novice buyers, unscrupulous sellers often claim to have "provenance" or documented ownership histories that confirm the authenticity of their art. In some cases, this so-called provenance dates right back to the artists themselves. (Problem art may also be accompanied by certificates of authenticity, abbreviated "COA" in online auction descriptions. To evaluate a certificate of authenticity, read Is Your Certificate of Authenticity Worth the Paper It's Printed On?)

Provenance can take many forms:

A signed certificate or statement of authenticity from a respected authority or expert on the artist.

An exhibition or gallery sticker attached to the art.

An original sales receipt.

A film or recording of the artist talking about the art.

An appraisal from a recognized authority or expert on the artist.

Names of previous owners of the art.

Letters or papers from recognized experts or authorities discussing the art.

Newspaper or magazine articles mentioning or illustrating the art.

A mention or illustration of the art in a book or exhibit catalogue.

Verbal information related by someone familiar with the art or who knows the artist.

Good provenance almost always increases the value and desirability of a work of art because, first and foremost, it authenticates the art. Good provenance also provides important information about and insight into a work of art's history. Unscrupulous sellers know the value of provenance and often go to great lengths to manufacture or concoct phony provenance for their art. The good news is that phony provenance is relatively easy to detect in most cases. The following guidelines will help protect you from buying art with fake or questionable provenance:

* NUMBER ONE: NEVER BID ON ART WITHOUT SEEING THE PROVENANCE FIRST. Sellers may say they have provenance, but will only show or give it to winning bidders. Other common excuses for not showing provenance include protecting the privacy of the previous owners or keeping bidders from contacting previous owners. In most cases, the real reason for not showing the provenance is that it's questionable in nature. If you can't see it, don't bid.

* Provenance must specifically mention the piece of art that's being offered for sale in order to be valid. Documents that do not specifically mention the piece of art in question do not constitute valid provenance.

* Photocopies of letters, certificates, and other documents are not valid forms of provenance (unless the originals are at a known location, and can be accessed and inspected firsthand). Documentation must be hand-typed, handwritten, hand-signed, hand-stamped, or otherwise original.

* Provenance is fact, not supposition. Statements that a particular work of art looks similar to other works of art by the artist are not provenance (unless they're made by internationally respected and credentialled authorities on the artist and can be documented as such).

* Get full names and contact information for all private parties that the seller claims previously owned the art. Confirm that these people actually exist (or existed) and, whenever possible, speak directly with them or their descendents. Just having names is not enough.

* Names of previous owners do not constitute valid provenance unless they provide concrete and irrefutable proof that the work of art in question is by the artist who the seller says it is by. For example, a previous owner is mentioned in an exhibit catalog as beeing the owner of the particular work of art in question.

* Get full names and contact information for all galleries or auction houses that the seller claims previously owned the art. If these galleries are still in business, contact them in order to confirm that the information provided by the seller is correct. If none of the galleries or auction houses are trackable, then this may be cause for concern.

* Names of galleries or auction houses that previously owned the art do not constitute valid provenance unless they can provide concrete and irrefutable proof that the art is by the artist who the seller says it is by. Just because an auction house sells a work of art does not automatically make that work of art genuine.

* All statements sellers make about who owned the art or where it came from must be verified. Conditional or third party statements like "this art is believed to have been owned by..." or "the person I got it from told me..." or "the estate that this came from had lots of important art..." do not constitute valid provenance.

* An illustration of the art taken from an old auction catalogue does not constitute valid provenance unless the auction house is or was able to demonstrate beyond doubt that the art was by the artist in question. For example, the auction house may have sold it as "attributed" to the artist.

* An appraisal for the art does not constitute valid provenance unless it is by a respected expert or authority on the artist, and states that the art is absolutely by the artist. If you have any questions about an appraisal, contact the appraiser before bidding on the art and verify that appraiser's qualifications to make any statements of authenticity contained within the appraisal. Such an appraiser would also have to be a nationally or internationally respected authority on the artist in question. When you can't contact the appraiser or the appraisal does not include adequate contact information, don't bid on the art. (FYI, an appraisal normally assumes the art is genuine; it is not in and of itself an authentication of the art. In other words, you need a separate authentication or provenance to go along with such an appraisal.)

* When a seller states that a work of art is "attributed to" a particular artist, get the name of the person who did the attributing. If that person is not an expert on the artist, then the attribution is meaningless. Furthermore, an attribution, no matter who makes it, does not constitute valid provenance.