Archival Storage on Disc FAQ

Data Storage - Archival Storage 

What is the best sleeve material for archival use of DVD media? 
 
We can recommend an archival sleeve, but first and foremost a better overall choice would be a case in which the disc surface does not touch any surface, like a  jewel case or  DVD case.  A black DVD case is ideal in that it keeps light off the disc, as well. 
 
If you require space saving sleeves for storing your DVDs and CDs for archival purposes, we highly recommend sleeves made from Tyvek.  Tyvek offers features paper can’t in protecting your disc: 

  • Tyvek does not scratch the disc like paper. Paper is much more abrasive. Think of using papertowels to wash your car. 

  • Tyvek does not create dust, where paper does. It's always a good idea to keep dust out of your drive and off your disc. 

  • Tyvek is not going to break down when it gets wet. 

Other notes: Tyvek’s weight is much less than paper, which adds up when you buy a case. You will also want to avoid a sleeve with a clear window, as they can bond with the printed disc surface over long term storage. So overall, Tyvek sleeves are much better suited for storage. 
 
Can you send me information regarding the life span of CDs and DVDs? We are using CDs/DVDs to archive data. 
 
The story on DVD and CD life span differs a little, so let me break it out for you. Some document links on shelf life are listed below. 
 
CD-R 
CD-R life is determined by two factors, recording dye composition and reflective layer. Phythalocyanine dye has the longest shelf life, but the life can vary by manufacturer, so not all are created equal. Phythalocyanine is the dye that creates the "real cd" look many consumers and replicators look for, so it is used by many of the lowest priced manufacturers, who may not have the best formula or usage. Cyanine dye CD-Rs (Taiyo Yuden) have a shelf life of about 30 years, but the bigger issue with Cyanine CD-Rs is the way they are impacted by light. Leave a Cyanine CD-R on the seat of your car, and you'll lose the content quickly. Leave a Phthalocyanine dye in the same place and you'll find it much less susceptible to light damage. Any CD-R you use should be kept away from direct sunlight just to be safe. The story with reflective layer is simple. A disc with silver reflective layer is subject to oxidation, where a gold reflective layer is not. So any gold reflective layer disc is going to have a much longer life.
 
DVD-R 
Unfortunately DVD Recordable isn't the same easy group of answers. Check with a manufacturer about why their particular DVD works best, and you'll get comparisons to their CD-R quality and broad statements about overall quality, which are hard to measure or prove. Right now the only manufacturer that has done expanded work on DVD shelf life is Verbatim. The AZO dye used by Verbatim has specific long-life characteristics. The AZO dye shows lower error rates after 600 hours of aging, where the specification is below 280 hours. No one has done more testing on the light sensitivity of dye than Mitsubishi Chemical, which is the parent company of Verbatim. Another aspect of DVD disc quality is the bonding agent, which keeps the two-piece DVD disc together. A DVD recordable is made of two thinner discs, which are held together by bonding glue. The ability of the bonding glue to resist breakdown in extreme conditions is a key part of the disc quality. We see many DVDs, which are damaged from impact on the side, where the impact separated the two discs, damaging the dye and reflective layer. Using a premium bonding glue can dramatically increase the performance of the discs in aging test. Tests have show the premium Verbatim product can again exceed over 600 hours of aging, while some media with one particular bonding glue showed increased errors at outer areas. 
 

Archiving 

Our company has been in the CD-R business for years and we've worked with many clients who use discs for archiving. Here are some tips we recommend to clients.... 

  1. Anytime you plan on long-time storage, don't use paper labels. The paper is very sensitive to humidity. It can contract and expand. If the paper expands or contracts, the glue holding the paper to the disc surface can pull away the lacquer & reflective layer. The reflective layer sits right above the dye layer. When the reflective layer and dye layer pull away, the information on the disc will be lost. (This was an experience the Smithsonian had with some archived discs stored in a cabinet/locker that was very dry).

  2. Try to go with a true gold disc if you want to seriously archive. A gold reflective layer disc with Phthalocyanine dye has a shelf life of almost 300 years, compared to under 100 for a silver Phthalocyanine dye disc, and less than 30 for a Cyanine discs. Basically, the metal in the silver disc can oxidize, and the gold doesn't, so there's no breakdown of the reflective layer. 

  3. In general, avoid writing on discs with Sharpies. Use water-based markers. Ordinary felt tipped markers use solvents that can attack the protective coating on CDs and ruin your data or music. (You can tell by the strong smell of the felt tip whether it's solvent based). There hasn't been many reports of this actually happening, but long term storage simulation tells us this could be a problem down the road.

  4. The jewel case remains the preferred storage method for archiving, though some choose to use DVD cases,Tyvek sleeves or paper sleeves. We strongly recommend avoiding paper sleeves for archiving purposes. Paper creates more dust and is more abrasive than Tyvek. No matter how you choose to store your archive discs, make sure you store them vertically, never stacked. Keep the discs in a dark place, away from excessive heat and humidity, and try to avoid subjecting the archive discs to extreme temperature changes. Ultraviolet light, heat and humidity can cause damage to your discs. 

  1. When you have to handle the disc, always grip it around the outer edge. Never touch the recording surface.

  2. If you have to clean the disc, canned air is the best way to remove dust. If you get dirt that cannot be removed with canned air or fingerprints on the read side of the disc, use a disc or lens cleaning cloth in conjunction with disc cleaning solution or water, if needed. Wipe the disc from the center hub to the outer edge. Never wipe the disc in a circular motion.

  3. Always make an extra backup copy, just in case something happens to the original.