Copyright OSTA 2004
All rights reserved.

 

Understanding DVD

Author's Notes
Physical Logical and
ApplicationSpecifications

Recording Hardware
Recording Speed
Physical Compatibility
Disc Size Configuration and Capacity
Copying Deterrents and Content Protection
Duplication, Replication and Publishing
Disc Labeling
>Disc Handling, Storage
and Disposal

Disc Longevity
Disc Testing and
Verification

Disc Construction and
Manufacturing

Appendix A - Further
Reading and Resources

Appendix B - Industry
and Product Contacts
About OSTA
About the Author

 

 

 

 

 

Disc Handling, Storage and Disposal

What is the best way to handle and store a writable DVD disc?
A disc should always be handled by grasping its outer edges, center hole or center hub clamping area. Avoid flexing or dropping the disc and exposing it to direct sunlight, excessive cold, heat or humidity. Handle only when being used and do not eat, drink or smoke close by. Discs should be stored in DVD jewel cases or video boxes rather than sleeves because cases will not contact the discs’ surfaces and generally provide better protection again scratches, dust, light and rapid humidity changes. CD jewel cases can stress DVDs by gripping them too tightly resulting in discs being difficult to remove from CD cases without excessive flexing. As a result, use only containers specifically designed for DVDs and discs should always be removed carefully. Once placed in their cases discs can be further protected by keeping them in a closed box, drawer or cabinet. For long-term storage and archival situations it is advisable to follow manufacturer instructions. For further information consult the international standards for preserving optical media (ISO 18925:2002, Imaging materials — optical disc media — storage practices).

Should fingerprints and dust be cleaned off a writable DVD disc?
Like CD, DVD technology is robust and employs several design elements to minimize the effects of fingerprints and minor scratches on data integrity. The first line of defense comes from the physical structure of the disc and the location of the data-bearing marks and lands. The reading laser beam shines through the disc’s substrate focusing beyond the contaminated surface directly onto the marks and lands beneath. In concert with advanced error detection and correction capabilities minor debris and abrasions are largely ignored. That said, handling care should always be taken as above. A dusty disc should be blown off so that the dust does not enter the drive mechanism and accumulate on the lens or other optical components. It should be noted as well that fingerprints, dust and scratches have a greater impact on recording than is the case with reading a disc since contaminants reduce the effectiveness of the writing laser by obscuring its beam from the disc’s recording layer.

What is the best way to clean a writable DVD disc?
Dirty discs should be carefully cleaned using a soft dry lint-free cloth or camera lens tissue. Holding the disc by its outer edges or center hole gently wipe outward from the center hub toward the outside edge of the disc (just like the spokes of a bicycle wheel). Do not wipe the disc using circular motions, as any scratches created will do the least damage if they cut across the track of marks and lands. More stubborn fingerprints or stains can be removed using a soft lint-free cloth lightly moistened with water or a commercially available DVD/CD cleaning fluid. Do not use vinyl record cleaners, lacquer thinner, gasoline, kerosene, benzene or other solvents, as these may damage the disc. Manufacturer directions should always be followed.

Can scratched and damaged writable DVD discs be restored?
Often it is less expensive and makes more sense to transfer the data from a damaged disc onto a new one rather than to try to restore the problem disc. For dealing with more badly damaged situations consumer disc repair kits are available and several companies offer DVD restoration and resurfacing equipment and services. See the resource listing in the appendix for contact information.

Is it possible to recover data from damaged writable DVD discs?
Several software packages are currently available to diagnose disc problems and help recover deleted, unreadable or otherwise inaccessible information. A number of companies also offer commercial DVD data recovery services. See the resource listing in the appendix for contact information.

What is the best way to destroy unwanted writable DVD discs?
For office and high volume production situations various DVD destruction options are available including mechanical shredders, desktop devices that employ heat and pressure to make a disc unreadable and grinders that abrasively remove the disc’s reflective and data-bearing recording layers. Unlike a CD where data is physically located close to the disc’s top or label side, information recorded on a DVD resides in its interior. Consequently, not all devices that destroy CD-R and CD-RW discs are capable of properly dealing with writable DVDs. A number of companies offer commercial destruction services and deal with classified or other sensitive materials. See the resource listing in the appendix for contact information.

Can unwanted writable DVD discs be recycled?
A number of companies offer DVD recycling services and are able to reclaim some of the materials used in the disc’s construction. See the resource listing in the appendix for contact information.



 

CONTINUE TO DISC LONGEVITY