Photocopying in-house onto permanent durable paper provides a paper copy of fragile or brittle documents. In archival collections, preservation photocopies can be used to provide initial access so that researchers can identify which materials they need to see; to reproduce unstable documents (e.g., newsclippings, telegrams, and faxes); to provide copies of valuable documents that should be stored more securely; or to provide surrogate copies for materials that are too fragile to handle.
Traditional preservation photocopying, however, does not provide a master negative from which additional copies can be made, as microfilm does. If the photocopy becomes unusable, the original must be copied again, which can be problematic for fragile or brittle items.
The production of preservation facsimiles is an option for brittle books that are heavily used (e.g., for which a paper copy would meet the users' needs better than a digital or microfilm copy). This type of reproduction is normally contracted out to a vendor. Production of a facsimile is appropriate when duplicate edition copies (in better condition) or reliable reprints are unavailable and when other editions cannot provide an adequate substitute.
Preservation facsimiles were traditionally done using a photocopier, but now books are digitized and most libraries add the digital version to their digital collections repository. While it was once acceptable for the vendor to disbind the book in order to produce the preservation facsimile, digitization methods (using overhead cameras and careful handling) have improved and disbinding should no longer be practiced except in special cases. The digitized book is then printed on alkaline paper with a high-quality printer. The digitization process should produce a high quality, master file, which can be used to print additional paper copies in the future, without re-digitizing the original materials.
A high-quality preservation photocopy or preservation facsimile requires the use of permanent paper, as well as equipment and procedures that will ensure a long-lasting copy. Although there are no specific standards for preservation photocopying or for the production of preservation facsimiles, there are related standards and guidelines that cover elements of the process.
Paper used for preservation photocopies or facsimiles must comply with ANSI/NISO Z39.48 1992 (R2009) Permanence of Paper for Publications and Documents in Libraries and Archives (PDF). The standard sets out requirements for pH, tear resistance, alkaline reserve, and amount of lignin permitted. A partial list of papers that meet the ANSI/NISO standard is available online in an excerpt from North American Permanent Papers, 3rd Ed.
Procedures for ensuring the quality of scanned images in preservation facsimiles should follow guidelines and best practices for digital imaging that are generally accepted within the preservation community. See the Digitization section of this session for more information.
Copiers used for preservation photocopying must be kept in the best condition possible and should not be used for other types of copying. Carbon black toner must be used, and the adhesion of the image to the paper must be tested periodically. See the Library of Congress article Preservation Photocopying for detailed requirements.
It is best to contract out the production of preservation facsimiles, since complex machinery and procedures are involved. Small-scale preservation photocopying can be done in-house, but staff must be well trained in the proper procedures and the equipment must be properly maintained.
The basic procedures involved in producing preservation photocopies and facsimiles are as follows:
- Preparation—The materials to be copied are examined page-by-page to ensure that they are in the correct order and nothing is missing. If there are foldouts or other oversize materials in a bound volume, these are measured.
- Photocopying— During the photocopying process, a daily peel test (refer to the National Archives and Records Administration's Peel Test for more information) is recommended, to ensure that the image is adhering properly to the paper. When photocopying two-sided pages, care must be taken to ensure that the placement of the text or image on the verso and recto sides of the pages are maintained in relation to each other. Oversize and color materials may be copied separately as needed.
- Digitization—Digitization techniques and equipment have advanced such that items should no longer need to be disbound, except in special cases. The institution must specify how illustrations will be scanned (gray scale, color), at what size foldouts will be scanned, etc.
- Inspection—Once copying or digitization is complete, the finished product is inspected to ensure that there are no pages missing, the copies are legible, the contrast is good, and the general quality is acceptable compared to the original.
- Binding—Paper copies are bound according to the NISO standard for library binding (see Session 4: Library Binding). A statement is placed in the copy identifying it as a preservation photocopy; this should be noted in any catalog records as well.
- Storage—The copy or copies should be stored according to guidelines for paper-based collections. The original items may be retained after photocopying in case additional copies or another type of reformatting is needed in future. For books that are brittle or that have been disbound, the loose leaves can be foldered and boxed.