here seems to be a misconception, when we have to consider a painting a forgery. And as modern scholars tend to complicate simple matters and provide rather useless ideas for the connoisseur, lets drop some words on this.

It is simple. When a painting gets intentionally attached during its existence

a name of an artist who had not produced it, it is a forgery. It does not matter for what reason, or whether the painting was intended from the beginning to be a forgery, it is a forgery.

Usually a painters signature or seal is used to do it, but the case of a manipulated reference, or a wilful wrong attribution should be included as well.

As one can't trust any self declared specialist, not even the author of this, so one also cant blame them in the end for accepting a good forgery.

Here is not the place to discuss how the connoisseur should handle the situation. We already made an attempt of giving a tool set to understand quality here, and how to approach authentication here.

This essay is to explain what happens at the other end, what you need to expect.

The range of methods to produce a forgery is wide:

- We have all sorts of intended copies.

- Ghost painters produce paintings just in the style of a famous artist.

- A useful or less useful existing painting, unsigned, or signed by an undesired artist, gets attached with a wrong signature.

- Paintings are wilful wrongly attributed by creating reference letters (copies or originals taken from another painting), inscriptions etc..

- A false provenance is established with forged material and lies.

Any combination that works will be used, to be even more convincing.

As there is long tradition of collecting, accepted forgeries became the base for a next generation of forgeries and on, and on.... Also we may find a early successful forgery praised later intensely and honestly as a fine original.

And of course on the other side, the omnipresence of forgeries looming over everybody is creating panic, so that many good and correct paintings are denounced as false and wrong too.

To copy a fine painting for the purpose of study a composition and training the brushwork is a regular method of learning. But a honest copy is signed not with a wrong name. Its not a forgery. But later though, such a work might be turned into a forgery by attaching the wrong signature.