Prints by artists today may potentially retain their financial value as art (i.e., as an appreciating investment) because they are created by an artistic process rather than by a strictly mechanical one, and may become scarce because the number of multiples is limited.In Rembrandt's time, the limit on the size of an edition was practical: a plate degrades through use, putting an upper limit on the number of images to be struck.
In monotyping, a technique where only two impressions at most can be taken, prints may be numbered 1/1, or marked "unique". C." or "H/C", meaning "hors de commerce", not for sale.
Artists usually print an edition much smaller than the plate allows, both for marketing reasons and to keep the edition comfortably within the lifespan of the plate. These are usually prints reserved for the publisher, like Artist's Proofs.
However, it was not until 1986 that more comprehensive provisions, still in place today, were enacted with the passage of the "Georgia Print Law".
That law became the template for statutes subsequently enacted by other states.
Most modern artists produce only limited editions, normally signed by the artist in pencil, and numbered as say 67/100 to show the unique number of that impression and the total edition size.
An important and often confused distinction is that between editions of original prints, produced in the same medium as the artist worked (e.g., etching, or lithography), and reproduction prints (or paintings), which are photographic reproductions of the original work, essentially in the same category as a picture in a book or magazine, though better printed and on better paper.
These may be marketed as "limited editions" with investment potential (which is rarely realized), and even signed and numbered by the artist.
Some knowledge is often required to tell the difference.
In this category one sometimes finds monotypes, monoprints, collagraphs, altered prints with collage or chine colle additions, or even hand-colored prints.
There remain artists who are strong advocates of "artist's prints" which are conceived, printed, signed, and given the edition number 1/1 by the artist.
Until the 19th century, in the period of the Old master print the concept of an edition did not really apply to prints, unlike books.