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Understanding Blank Write-Once CD & DVD Media
Picking Blank CD & DVD Media
Standing in front of a blank media wall at a local superstore can be very intimidating. Oftentimes, there are so many options, it can take a long time to finally select one. There are different colors, brands, and types, and the prices vary just as much as the selection. With a little know-how, selecting a blank disc can be much less overwhelming.
Not all blank media is made the in the same way. There are variations in the materials used and manufacturing process that can affect how long the disc will last, how reflective it will be, and whether or not it will play in one particular player over another. Rewritable discs like CD-RW, DVD-RW, DVD-RAM, and DVD+RW work on very different principles than write-once discs like CD-R, DVD-R, and DVD+R. The information in this article is focusing on write-once media, and how to differentiate them.
There are many things that make buying blank media confusing. Things like brand and disc color often confuse shoppers, which lures them into buying one disc type over another for the wrong reasons. Below are some of the things to look for when purchasing blank media.
Disc Type
Disc type refers to whether or not it's a CD-R, DVD-R, or DVD+R. It's necessary to know what type of disc it is that you need to buy before considering any of the other factors.
The different colors of "write-once" recordable discs (such as CD-R, DVD-R, and DVD+R) come from the combination of the reflective metal layer and the dye formulation in the recordable layer. The metal layer is usually silver or gold, while the recording layer color is based on the dye. Today, there are several combinations and variations of dye formulas, but most are based on the basic ones below. Some of the common dyes are:
Cyanine
Dye color: blue / Patented by: Taiyo Yuden
Cyanine is one of the oldest dye formulations found in recordable discs. It is chemically unstable, and somewhat sensitive to light. Cyanine discs are not usually recommended for archival purposes since they can cheimally breakdown after a few years. Many companies use proprietary additives to make the formulation more stable, and therefore improve their archival life up to 50 years. Cyanine discs will usually appear blue in color, but can appear green when coupled with a gold reflective layer. Cyanine is more tolerant of variation during the writing process, and since it is a sensitive material, is recommended for high speed recording.
The majority of blank media is produced with Cyanine. It can be the least expensive kind of disc to manufacture, and can provide excellent results for the money. The adaptation of this dye formulation by other blank media companies, such as Fuji and TDK, can yeild similar performance to other dye formulations. Although Cyanine is typically the cheapest of formulations to use, additives and other factors can make these discs just as expensive as others on the retail shelves.
Recommended uses:
Mix CD's
Short-term Data Storage
Sharing photos with friends and family
High speed recording (Recording at greater than 32X speeds)
Phthalocyanine
Dye color: clear / Patented by: Mitsui Toatsu Chemical
Since the dye is clear, these discs are usually a silver, gold, or a very light green in color, depending on the color of the reflective metal layer. Phthalocyanine formulations are extremely stable, and can have a archival life of hundreds of years, as well as top-notch performance. Phthalocyanine is a more difficult substance to write to, and is less tolerant in power of the laser during the writing process. Therefore, it is not recommended to use Phthalocyanine for high speed recording.
Phthalocyanine seems to be the second most common dye formulation used in blank media. Since the dye itself is clear, discs of these types tend to have the highest reflectivity of any blank medium. Where older drives have difficulty reading other types of blank media, these types of discs will most likely be compatible. However, the cost of quality phthalocyanine discs tend to make other dye formulations more attractive.
Recommended uses:
Long term data storage, such as photos and documents
Duplicating CDs
Duplicating DVDs
Working with older playback devices
Holds up better in extreme conditions, like exposure to UV light
Azo
Dye Color: blue / Patented by: Verbatim & Mitsubishi Chemical
Azo is a very stable dye formulation which can last for decades. Though typcially more expensive than cyanine formulations, azo discs can yeild very high performance with good durabiltiy for the money. Azo discs are usually dark blue in color.
Azo looks similar to Cyanine blank discs (given the blue color), but offers substantial performance gains. When coupled with a silver reflection layer, Azo is more reflective than Cyanine. It should be noted that although Azo is more stable over the years, additives in Cyanine can provide similar longevity to Azo. Azo is usually more expensive than a regular Cyanine disc, but advanced Cyanine formulatons could be more expensive.
Recommended uses:
Good cost for performance ratio
Long term data storage (Under 50 years)
Duplicating CDs
Duplicating DVDs
Formazan
Dye color: light green / Patented by: Kodak Japan Limited
Formazan is a hybrid of Cyanine and Phthalocyanine, origianlly developed by Kodak. The dye itself is light green, but the disc looks like a dark green when coupled with a gold metallic layer. Formazan is a rarely used formulation in the blank media industry. If available, Formazan can be an exceptional quality disc for reflectivity, write speed, and longevity. However, the cost of Formazan typically leads buyers to Phthalocyanine for their recording purposes.
Recommended uses: See Phthalocyanine
Regardless of the color, understanding the dye formulations doesn't necessarily tell you everything when choosing a blank disc. Dye formulation can give an idea of the expected longevity and performance of the disc, but there are other factors, like how well it was made and how the disc is stored, which can affect how long the disc will perform and last over the years. Also, the dye does affect the reflectivity of the disc, which may or may not work in some players.
Unfortunately, not all manufacturers are up front about what dye formulations they use for their blank discs. You may find a reference to dye on the packaging, but they rarely state what they use. The majority of blank disc makers use cyanine, or some proprietary adaptation of it. However, you can usually figure it out based on the color of the disc usuing the information above. Also, there are some freeware programs available that will scan a blank disc and give you information about a discs compostition.
Brand
Branding is not always a critical factor when seclecting a quality blank disc. However, off brands at low-prices could mean that the disc is poorly constructed, negating it's useful life and readability. Even with the best dye formulations, a poorly constructed disc will not perform well. Big names in blank media tend to be more expensive than others, and often have their own variations on formulas that make them better or worse than other makes. Even top names in blank media won't work in all players, so don't bet on brand alone when picking out blank media.
Tips for Picking the Right Blank Media
Buying CD or DVD media for long-term storage may be a ridiculous notion, considering in 50 years there may not be any device capable of playing a CD or DVD. Oftentimes, a blank disc needs to hold archival data long enough to be copied to whatever the latest form of storage is. I would expect that just about everyone has copied everything on their old floppy discs to a blank CD or DVD. The same will hold true for future formats. Remember how excited you were when you discovered every floppy you had fit on one CD? Someday all of your CDs or DVDs will fit on one (insert future format here).
Here are some things to consider when purchasing blank media:
Try different types of brands with your hardware to find one that works for you.
If buying blank discs for the first time, do not choose a pack that contains 50 or 100 discs. Choose a pack that has five or less so that you can try it before you spend the farm on a bunch that do not work in your player.
Use price as a guide to find quality discs, but know that expensive doesn't always mean better.
Figure out what you're using the disc for. For things like burning mix CDs, or temporary data storage, inexpensive Cyanine discs are great.
Cyanine discs are easier to burn, especially at higher speeds.
Phthalocyanine can be read by most older CD or DVD drives.
Many in-house branded products are made by quality companies. Others are not.
Proper care & handling will affect the discs life more than the dye formulation.
