6. Selection of best copy and carrier restoration

An archive may possess multiple copies of certain content, perhaps including commercial audio recordings or motion picture films. Where holdings include more than one copy, the best example should be selected before reformatting its content. In the case of magnetically recorded or file-based sound or video recordings, an archive or production house may hold multiple versions for different purposes, e.g., a master version and a copy made for some form of distribution. Here again, care should be taken to select the most appropriate copy prior to reformatting. Additionally, cautious and appropriate cleaning and restoration procedures may be necessary to optimise signal retrieval and reproduction.


With mass replicated carriers—specifically mechanical and optical carriers—the replay quality of different copies may vary considerably because of the way that they have previously been handled and stored. It may therefore be advantageous to extend the search for the best copies to other collections on a national or even international scale (see section 16).

Non-replicated recordings may often be available in two or more versions. For example, a recording held on its original carrier (tape, cassette, film etc.) may also have been copied to an archival master. While the archival master (or subsequent generation copy in general) may often be in better physical condition, it may be of inferior signal quality due to poorer earlier transfer technology and the unavoidable signal degradation caused by the analogue copying process. Consequently, the signal quality of the various available copies must be compared.

Appropriate cleaning and restoration procedures can significantly improve signal retrieval. However, utmost care must be taken to balance any potential benefits against the risk of further deterioration, caused by subjecting fragile or deteriorating carriers to such procedures. It is good practice to minimise the handling of carriers at all times.

Some carriers may be so heavily deteriorated that even an attempt to replay them might place their content at risk. In such cases, a careful and informed evaluation needs to be made between the likelihood of damage through replay immediately, or through delaying replay until a less risky replay technology becomes available.