After an article has been accepted, all edits finished and finally published, some (many?) journals mail 10 or so printed copies of the completed article to the author. Not full copies of the entire journal issue but just the single article. I believe traditionally this was done so an author could prove to their institution that the article was indeed accepted and published. This is still standard practice for journals in South Korea where I live. I'm aware of the Korean word used for them but colleagues have been asking me what to refer to them in English and I couldn't offer an answer. Is there a special name in English for these copies? The best I could think of was just "excerpt". Other terms I've found that don't seem to fit: "advance copy", "proof copy", "galley proof", "final proof"
They are called offprints. From Wikipedia:
An offprint is a separate printing of a work that originally appeared as part of a larger publication, usually one of composite authorship such as an academic journal, magazine, or edited book. [...]
Offprints are used by authors to promote their work and ensure a wider dissemination and longer life than might have been achieved through the original publication alone. They may be valued by collectors as akin to the first separate edition of a work and, as they are often given away, may bear an inscription from the author. Historically, the exchange of offprints has been a method of correspondence between scholars.
The name I know these by is "reprints" or often "author reprints" in the context of those printed for the authors' use and distribution.
These are prints in the form of the final published article (rather than a pre-published form which are typically called 'proofs' and are often not a completely final version; these in my experience are always digital).
Although "reprint" seems to imply they are done after other publishing, in my experience they are offered immediately to authors, though many journals now simply provide authors with PDFs to distribute.