Monday, December 15, 2008

Care and Handling of CDs and DVDs: A Guide for Librarians and Archivists


Care and Handling of CDs and DVDs: A Guide for Librarians and Archivists

by Fred R. Byers

October 2003

Copublished by Council on Library and Information Resources and National Institute of Standards and Technology

Contents

National Institute of Standards and Technology
About the Author
Author's Acknowledgments
Quick Reference Guide

1. Introduction

1.1 Scope of This Guide
1.2 Use of Terms: Information, Content, and Data
1.3 Comparative Stability of Optical Discs and Other Media
1.4 CDs and DVDs: Operation and Variety

2. Ensuring That Your Digital Content Remains Available

3. Disc Structure

3.1 Polycarbonate (Plastic) Substrate Layer
3.2 Data Layer
3.2.1 Data Layer in ROM Discs
3.2.2 Data Layer in R Discs
3.2.3 Data Layer in RW and RAM discs
3.3 Metal (Reflective) Layer
3.3.1 Metal Layer in RW, ROM, and RAM Discs
3.3.2 Metal Layer in R Discs
3.3.3 Metal Layers in Double-Layer DVD-ROM Discs
3.4 Lacquer (Metal Protective) Layer (CDs)
3.5 Optional Surface Layer

4. How Long Can You Store CDs and DVDs and Use Them Again?

4.1 CD-ROM, DVD-ROM Discs
4.2 CD-R, DVD-R, DVD+R Discs
4.3 CD-RW, DVD-RW, DVD+RW, DVD-RAM Discs

5. Conditions That Affect CDs and DVDs

5.1 Environmental Conditions
5.1.1 Temperature and Relative Humidity
5.1.2 Light Exposure
5.1.3 Moisture
5.1.4 Organic Solvents
5.1.5 Magnetism, X-rays, Microwaves, and Radiation
5.1.6 Individual Disc Storage
5.2 Surface-Handling Effects
5.2.1 Scratches on the Laser-Reading Side of CDs and DVDs
5.2.2 Scratches on the Label Side of CDs
5.2.3 Scratches on the Label Side of Single-Sided DVDs
5.2.4 Fingerprints, Smudges, Dirt, and Dust
5.2.5 Marking
5.2.6 Flexing
5.2.7 Application of Adhesive Labels
5.2.8 Disc Surface Printing
5.3 Wear from Disc Play

6. Cleaning

Appendix 1: Commercially Available CD/DVD Disc Types
Appendix 2: Optical Media Drive Types and How They Handle Different Disc Types

Glossary
Bibliography

Tables

Table 1: Disc type, read/record type, data layer, and metal layer
Table 2: Dye type and color appearance—CD-R discs (recordable discs)
Table 3: Recommended storage parameters from different sources

Figures

Figure 1: User-removable storage-media timeline
Figures 2, 3: Layers that make up ROM discs
Figures 4, 5: Layers that make up R discs
Figures 6, 7: Layers that make up RW and RAM discs
Figures 8, 9: Two types of double-layer, single-sided DVD-ROM construction
Figures 10, 11: Two types of double-sided DVD-ROM construction
Figure 12: Printable or markable areas of the disc

Source: http://www.clir.org/pubs/reports/pub121/contents.html