CD-R Discs

Don't use CD-RW discs! They're only designed for short-term storage, and are erasable. 

Don't go putting your important files on these!

CD-R discs incorporate a photosensitive dye layer where your data is stored--it's what gets "burned" when you write to the disc

This layer is where your data or music is stored in the form of "pits" which are oblong areas that are discolored by the writer. These pits are read by the player and ultimately transformed into the "1s" and "0s" that make up your digital information (music and data look the same to the reader).

The accuracy of the stored information is directly affected by how this dye reacts. That's why the dye is so important.

The dye used is probably the most important for long-term stability and lifespan.

    There are three dyes used today in CD-Rs, in order of preference.

• Phthalocyanine - inherently stable unlike cyanine dye which must be stabilized by the addition of other metals, etc.  Longest lasting under testing.  Expected life-spans exceeding 200+ years when coupled with gold reflective layers in cold storage. (color, light green on silver reflective surface; light yellow/green on gold reflective surface)

• Azo.  Only Mitsubishi/Verbatim makes this.  Up to 100 years, less stable than Phthalocyanine dye, but more so than cyanine dye. (color, very deep blue on silver reflective surface)

• Cyanine dye.  Chemically unstable alone, and must be stabilized.  Still, less stable than the other dyes in long-term simulation tests. However, the first made consumer CD-Rs used this and is part of the 'standard' all CD-RW drives must be compatible with. (color, green-blue/blue on silver)

You can use CDRIdentifier to read the dye information stored on the CD-Rs you buy as well, which is more reliable if you don't know which bottom colors represent which combinations.

CDRIdentifier: http://www.gum.de/it/download/english.htm

 

Besides dye, the reflective layer used affects long-term storage lifespan.

    There are three known types used today, in order of preference:

    A. Gold - yep, expensive, but from the bottom, it'll look like real gold.

    B. Gold + Silver - Only Kodak Ultima Silver+Gold CD-Rs use this (discontinued).  Their tests suggest this combination lasts longer than silver-looking only discs.

    C. silver. - not true silver, but silver looking.  Most discs produced today use this.  However, given that metals except gold corrode, corrosion of such surfaces (when the top laquer layer has been removed/scratched) can and will occur.

The longest lasting CD-Rs, based on longevity testing, use Phthalocyanine dye and Gold reflective layers.  Phthalocyanine with Gold&Silver reflective layers next, followed by Phthalocyanine and Silver and Azo and Silver.  Cyanine on anything (only silver today) is the worst performing disc.

Top Quality Name-Brands, in order of preference:

     A. Mitsui Gold CD-R - Phthalocyanine dye + Gold.
     B. Mitsui Silver, Ricoh Platinum - Phthalocyanine dye + Silver.
     C. Mitsubishi/Verbatim - Azo + Silver.
     D. Taiyo Yuden - Cyanine + Silver.

All the 'cheapies' are generally of poorer & more variable quality.  eg. those $15 / 100pk of no-name CD-Rs at www.microcenter.com and www.compusa.com are the worst in long-term longevity.

However, even the quality of cheapies today will last a few years before deteriorating (assuming no long sunlight exposure; a few hours in the sun will kill discs) and will work fine.  Great for disposable burns, music, and stuff you don't care if they fade away soon.

The poorest performing brand-name disc, will still last 10-20 years in cold storage w/o any problems at all!

     Remember to keep them away from sunlight/UV, and that most likely, you'll be moving all of the data off CD-Rs onto newer storage medium (maybe DVD-R? Holographic?) in 10-20 years.  Why?  Not one storage medium has lived that long, and realistically, you'll want to move the data off obsolete storage media =before= they stop making the drives!!

     Just like nobody has 5 1/4" (or 8/12") floppy drives anymore, expect only to need at the minimum discs that'll last until you migrate the data off them in 10-20 years from now. 

http://fusion.zejn.si/

• Handle the disc only by the outer edge to prevent fingerprints and smears on the surface.

• Never touch the recording surface (unlabeled side) or set it down on a hard surface.

• Store the disc in its protective case. Proper storage helps protect the data from damage due to scratches on the disc surface.

• If dirty, clean the surface with canned air. Cleaning by wiping the surface is not recommended

• Never use a ball point pen or any other sharp object to label your discs. Using a felt tip pen is the easiest and fastest way to label a CD-R. Note, however, a few caution items. Some chemical properties of the ink can actually permeate the disc surface and cause damage to either the reflective layer or dye layer below the surface. Never use a solvent-based permanent marking pen on the top surface in the data area. The absolute safest area to label your CD-R is in the clear center near the center hole (any marker can be used here). A water based, permanent marker is recommended when labeling the top surface.

• Do not attempt to erase anything that has been written on the surface of the disc.

• If you will be using any adhesive labels or stickers, some precautions should be taken: Labels must be perfectly adhered to the disc surface. Any bubbling or creasing can imbalance the disc which can cause tracking errors or noisy spin ups. Never attempt to remove an adhered label. This can damage the protective layer or the reflective layer causing permanent damage to the disc. In addition, as with writing pens, insure that your labels' adhesive does not contain any chemical solvents that can become absorbed into the top layer. The adhesive on some labels have been known to damage discs. Labels can also become loose with age. Adhesive labels are not recommended for discs being used for archival purposes. (see list below)

• If you need to remove dirt or fingerprints from the read side of the disc, please follow these guidelines: Use a CD-cleaner cloth if available and wipe the disc from the inside to the outside, perpendicular to the tracks. (Lens cleaning cloths work well, or a clean cotton cloth. The cloth should be a “non-wood product” i.e. not a facial tissue or paper towel). Do not wipe in a circular motion around the disc, as this may scratch the disc ALONG the track if dirt is on the cloth. (Scratches ACROSS the disc are easier to correct than ones that follow the track) Commercially available CD cleaning liquid, ethyl or isopropyl alcohol, clear or soapy water can also be used. Do not use gasoline, kerosene, benzene, acetone, lacquer thinner, anti-static agents, or LP record cleaners as they may damage the recording surface.

• Use gold CD-R media for the best longevity

• Never touch the recording side

• Do not use adhesive labels

• Store vertically in a protective case

• Protective cases should rigid and contact the disc at the center hub only

• Store in room temperature at moderate humidity (below 50%)

• For labeling, use a water based permanent, felt tipped marker for writing on the top (write area) of the disc, or mark in clear center hub with any marker or ideally, write only on protective case

• Do not subject CDs to rapid changes in temperature or humidity

• Protect from light

• Never flex a recordable disc

• Store 1 copy offsite if possible.

MAM-A Gold Standard CD-R

 http://www.mam-a.com/Default.htm

Mitsui Advanced Media is the industry specialist at CD-R and DVD-R manufacturing. We produce a complete range of CD-R and DVD-R media, (once-only recordable discs) and hold a worldwide patent on one of the key components involved in the manufacturing process. 

Mitsui offers  the highest-quality and most durable recordable media available. Offering a wide range of CD-R and DVD-R media, it is chiefly designed for professionals and industry specialists who need to store, distribute and duplicate data.
CD-R technology As a chemical company, Mitsui Chemicals Inc. has spent 70 years gaining expertise with organic dyes. Since the laser which records the data burns the dye, it is a key aspect of the technology required to manufacture a high-quality CD-R. Indeed, Mitsui's greatest strength lies in its world patent on Phthalocyanine, the best organic dye currently available.

A CD-R contains