Libraries rely heavily on the first sale doctrine. This provision in copyright permits libraries to lend copies of materials they have legally acquired without infringing on the rights of copyright owners. In the first sale doctrine, the copyright owner's rights are exhausted after the first purchase of a new copy of a copyrighted work. After that initial purchase, the owner of the physical copy (such as a library) can lend, sell, rent, or otherwise distribute the copy without asking permission of the copyright owner.
Section 108 of the copyright code permits libraries to make archival copies for purposes of preservation within the following parameters:
Section 108 of the copyright code permits libraries to make single copies for a researcher's personal use within the following parameters:
Section 108 permits the borrowing and lending of works between libraries through a process called interlibrary loan.
Interlibrary loan arrangements cannot have "as their purpose or effect" that the library receiving the copies on behalf of requesting patrons "does so in such aggregate quantities as to substitute to or purchase of such a work." When the demand for a journal or other work reaches a certain level, the library should consider subscribing to or purchasing the work in question.
The CONTU (National Commission on New Technological Uses of Copyrighted Works) standards generally permit a library to receive up to five copies per year from the most recent five years of a journal title before purchase/licensing of the journal or articles is recommended.