access copy
n.
A reproduction of a document created for use by patrons, protecting the original from wear or theft; a use copy.
A digital object (typically a graphic) that has been scaled down from a high-quality original to a lower-quality, smaller version, to facilitate delivery over low-bandwidth networks.
Notes
Access copies1 may be made in a variety of formats. Photocopying was often used to make inexpensive access copies of textual documents and, usually with limited success, photographs. Access copies are now likely to be digital scans of the original. - An access copy2 is often derived from a high-resolution master scan. A master is useful for high-quality printing and reduces the chance that the original will need to be rescanned in the future, but it is typically very large. Creating an access copy that matches the lower resolution of video monitors significantly reduces the size of the file. Because these scans are often accessed through websites, the transmission time is reduced without apparent loss of quality.
