There isn’t a legal definition of what makes an edition.

Instead, an edition may be limited by contract (which can be verbal) and by making representations. So, for example, if the edition is said to be 8 plus an artist’s proof, it would be fraudulent to then make a 9th.
When nothing is said about the number in the edition or nothing is said about the limits of that edition, for example whether the edition only refers to works in that material or of that size, there isn’t a definitive answer.

Best practice would be to record details of the edition in writing and for each work in the edition to be clearly numbered, and accompanied by a certificate stating which number it is in the edition.

This article is from the Artlaw Archive of Henry Lydiate's columns published in Art Monthly since 1976, and may contain out of date material. The article is for information only, and not for the purpose of providing legal advice. Readers should consult a solicitor for legal advice on specific matters. Artists can get free online legal information from Artquest.