How To Choose CD/DVD Archival Media

(Last updated January 11th 2013)

Translations: Serbo-Croatian by Jovana Milutinovich

Ahh, I’ve been planning to write this one for awhile: an entire article on archival quality media. As I do professional software development as well as professional photography (what a weird combination), I need archival quality CD and DVD media to store my data on.

However, one of the hardest things to is actually find good media, or even understand why it is good media. This article focuses on the history of Compact Discs, writable CD/DVD media, and why DVD+R is superior to DVD-R. If you want to just know what media is worth buying, skip to the summary at the bottom.

Short history of the Compact Disc
The invention of the Compact Disc has had a large impact on both music and computing in the last 20 years. Invented in 1979 as a joint project between Sony and Philips to counter the self-destructive nature of consumer audio playback (such as tapes and records that could only be played so many times before the recording degraded significantly) by switching to a resilient digital format.

The CD was also designed to store standard computer data, as in 1985 the first CD drives for computers were released; massive, bulky, and expensive, it was not until the mid-90s that they really took off, driven almost solely by video games and large multimedia applications.

In 1990, Sony and Philips went back to the drawing table, and then came out with the CD-R, a record-once medium. Yet again, the first CD burners were large, expensive, and bulky, but by the late 90s having a CD burner was the new ‘in’.

The first few generations of CD media, designed by Taiyo Yuden (a company who I respect, and buy all my archival quality media from), actually kind of sucked; it wasn’t until around 2000 that companies started producing very high end media.

CDs and DVDs store individual bits (encoded in various ways depending on the media) with spots of reflective and non-reflective areas. This method is called ‘pits and lands’, where pits ‘absorb’ light (ie, are ‘off’ bits) and lands ‘reflect’ light (ie, are ‘on’ bits).

With pressed media, the pressing method causes pits to reflect the laser’s light away from the sensor, and the lands to reflect it back at the sensor. With burned media, a high energy laser causes spots of organic dye to go opaque and obscure the reflective surface for the pits, leaving the organic dye for lands alone.

Short history of the DVD
While burning was becoming popular in the late 90s, so was playing high quality video on DVDs. Storing almost 7 times the data of a 700MB CD (or almost 13 in the case of dual layer DVDs), allowed companies to store massive amounts of data on one disc, leading to the movie industry to drop VHS tapes and the video game industry to drop CDs.

In 1995, the first DVD specification was ratified by over a dozen companies including Sony and Philips, as well as Thompson, Pioneer, and Mitsubishi. By 2000, at least half the homes in the US and Japan had DVD players.

So, obviously, the next step was to produce burnable DVDs. Two separate, and incompatible, efforts took hold. The first one, Pioneer’s DVD-R (pronounced ‘DVD dash R’) was released in 1997, using different data storage methods than pressed DVDs (appearing to be more like CD-R than DVD), a poor error correction scheme, and the ‘wobble’ laser tracking system of DVD-R is inadequate for the job.

The second effort, lead by the DVD+RW Alliance (headed by Sony, Philips, Mitsubishi, and Thompson) was released in 2002, as an alternative to the poorly implemented DVD-R. DVD+R uses a superior ‘wobble’ laser tracking system, a far better error correction method, and the media quality itself is typically higher. (See the ‘Why DVD+R?’ section below for a more technical explanation)

Why archival media is hard to produce
Unlike pressed CDs/DVDs, ‘burnt’ CDs/DVDs can eventually ‘fade’, due to five things that effect the quality of CD media: Sealing method, reflective layer, organic dye makeup, where it was manufactured, and your storage practices (please keep all media out of direct sunlight, in a nice cool dry dark place, in acid-free plastic containers; this will triple the lifetime of any media).

The silver and aluminum alloys used in virtually all blank CD/DVD media has one major issue, requiring the manufacturer to lacquer a protective seal over the entire disc: silver and aluminum oxidize when they hit air, turning the normally reflective layer into silver or aluminum rust. Some (very expensive) media uses gold instead which doesn’t oxidize, however DVD media cannot use gold due to design issues (not true anymore, see update 1 below). Today, only the cheapest of the cheap media has severe issues with sealing practices (as such, avoid any media made outside of Japan and Taiwan; especially avoid media made in India).

Assuming that the protective seal and reflective layer are manufactured correctly, the next issue is the organic dye. The first organic dyes, designed by Taiyo Yuden, were Cyanine-based and, under normal conditions, had a shelf life of around ten years; simply, that was simply unacceptable for archive discs. Taiyo Yuden, Mitsubishi Chemicals, Mitsui Co., and Ciba Specialty Chemicals spent the next ten years trying to produce the best organic dyes, eventually reaching archive-quality CD media.

Taiyo Yuden produced ‘Super Cyanine’, a chemically stabilized version of the original Cyanine dye designs, while TDK offers media that uses ‘metal-stabilized Cyanine’ dye, leading to similar shelf lives as Taiyo Yuden’s media. Taiyo Yuden states their Super Cyanine dye is chemically stable for at least 70 years, and TDK states their metal-stabilized Cyanine is also stable for 70 years.

On the other hand, Mitsubishi went in a different direction and produced what is called a Metal Azo dye, that they claim is stable for around 100 years. Azo dyes are chemically stable, however, the shelf life of media using Azo dyes typically does not exceed that of Super Cyanine and metal-stabilized Cyanine.

The third dye produced for CD media is called Phthalocyanine dye, with the majority of such dyes produced by Mitsui and Ciba. Typically marketed as more resistant to heat and UV radiation than Cyanine and Azo, modern Cyanine and Azo dyes last just as long in extreme conditions.

DVDs also use similar dyes, however manufacturers have intentionally kept what dyes they use a secret (instead of a feature in their marketing of the media), and all blank DVDs are intentionally the same color (as different dyes on CDs make blanks different colors, however, it is not indicative of what dye is used due to some manufacturers using different colored silver alloys and non-reactive additives in the dye).

Why Taiyo Yuden media, and how to buy in the US
The best discs in circulation tend to be Taiyo Yuden media. In Japan, you find their media under the brand That’s, which are wholly owned by Taiyo Yuden.

As of late 2009, Taiyo Yuden announced they were buying the JVC Advanced Media brand, and making it a wholly owned and operated brand for TY products. They did this to put Taiyo Yuden products on store shelves worldwide. See update 4 at the bottom for a full explanation.

Simply put, I have never had problems with any kind of Taiyo Yuden media. Ever. I have bought CDs and DVDs under a dozen different brands (including non-Taiyo Yuden manufactured TDK and Verbatim), and the only ones that have had a 100% success rate is Taiyo Yuden.

If you cannot find any company selling media under the Taiyo Yuden/JVC Advanced Media brand, I suggest buying from the SuperMediaStore.com, who offer a wide range of Taiyo Yuden CD media, DVD-R media, and DVD+R media. I tend to buy just from them, as they are the only company that guarantees that their media is actually from Taiyo Yuden and not a fake (see the above linked FAQ on information about fake Taiyo Yuden media).

Why DVD+R?
This is the most technical section of the article. If you don’t understand the basics of how CD/DVD media works, or find such technical discussions boring, skip to the next section.

As I said earlier, DVD-R sucks for data preservation for three reasons: inferior error correction, inferior ‘wobble’ tracking, and the fact its data writing methods look like an un-needed halfway point between CD-R and DVD+R. The wobble tracking I shall explain first, then the error corrections method, then the specifics of ATIP/pre-pit/ADIP optimum power settings.

For a CD/DVD burner to track where it is on the disc, it uses three things: the ‘wobble’ of the data track (where it actually wobbles back and forth instead of in a straight line) to tell where it is in the track, the position of the track to tell where it is on the disc, and some additional information on the disc to tell where the track (singular, as CDs and DVDs only have one track, and it is written in a concentric spiral) begins and ends.

This additional information on a CD-R is called the ATIP (Absolute Time In Pregroove), which contains how long the track is, where it begins, what the maximum and minimum writing speeds are, what formula dye it uses, who actually made it, optimum power control settings, and error correction data. The ATIP is stored as a frequency modulation in the wobble itself.

However, since the wobble changes subtly to encode data, it is impossible to use with the small size of tracks DVD requires, as electric noise in the laser pickup and wobbles introduced by the electric motor spinning the disc, these could easily be read as frequency changes in the real track itself.

On DVD-R, they tried to solve the problem with something called ‘pre-pits’ where spikes in the amplitude of the wobble appear due to pits fully out of phase with the rest of the track (ie, between two spirals of the track, where there is no data). This can be viewed as a simple improvement over CD-R as it makes it easier to track the wobble (since the wobble is constant except for the easy to detect and remove spikes).

Unfortunately, this method as one flaw: due to electric noise in the laser pickup, it would be very easy to miss the pre-pit (or read one that wasn’t actually there) if the disc were damaged or spun at fast speeds. The time to read a pre-pit is 1T (roughly .0000000038th of a second), which even for a computer can be easy to miss. DVD-R traded hard to track frequency changes for hard to read wobble-encoded data.

On a DVD+R, however, they came up with a much better method. Instead of changing the frequency of the wobble, or causing amplitude spikes in the wobble, they use complete phase changes. Where CD-R’s and DVD-R’s methods make you choose between either easy wobble tracking or easy ATIP reading, DVD+R’s method makes it very easy to track the wobble, and also very easy to encode data into the wobble. DVD+R’s method is called ADIP (ADdress In Pre-groove), which uses a phase change method.

With ADIPs’ phase changes, the direction of the wobble changes and continues on going in the exact opposite direction (ie, counter-clockwise to clockwise, or the reverse). For example, if the wobble was ‘going up’, the phase change causes it to instantly reverse direction start ‘going down’ no matter where it in the wobble cycle. The phase change is very easy to detect, and also continues for a set period (in this case, one 32T section of the track, or 32 times longer than the pre-pit method of DVD-R).

The state of the phase change (clockwise or counter-clockwise) encodes the individual bits in each block In essence, with the phase change method, not only do you have an easy way of tracking the wobble, but you now have an easy way of reading wobble-encoded data.

As I mentioned earlier, this wobble-encoded data includes error correction of wobble-encoded data itself. Error correction is the most important part of media, because if it does not work, then you’ve lost your data, even if there is nothing seriously wrong with the disc.

The DVD-R specification states that for every 192 bits, 64 of them are not protected under any scheme, 24 of them are protected by 24 bits of parity, and the last 56 bits are protected by another 24 bits of parity. This weird (to put it mildly) scheme allows you to easily scramble or lose 25% of the data that is required to read your disk! This information is almost more important than the actual data burned on the disc itself.

The DVD+R specification, however, states that for every 204 bits of information, it is split into four blocks of 52 bits containing 1 sync bit to prevent misreading because of phase changes, 31 bits of data, and a 20 bit parity (that protects all 32 bits of data). The sync bit is always the same value in all four blocks, and exists only to prevent phase inversions.

Now, the third item on the list: how DVD+R discs burn better. As I said earlier, ATIP/pre-pit/ADIP stores information about optimum power control settings. This information is basically formulas stating how much output power is needed, what the laser startup power should be, and other pieces of information you require to properly burn a DVD.

Optimum power control output is dependent on three things: burning speed, laser wavelength, and information given to the drive about the media. DVD-R basically fails on all three accounts because DVD+R simply includes far more information about the media in the ADIP data than DVD-R does in it’s pre-pit data.

DVD+R includes four optimum profiles, one for four major burning speeds (usually 2x, 4x, 6x, and 8x, though this can change as speeds increase). Each of these profiles include optimum power output based on laser wavelength, more precise laser power settings, and other additional information. With this information, any DVD+R burner can far more optimize it’s burning strategy to fit the media than it can with DVD-R, consistently providing better burns.

For comparison, DVD-R includes one profile, optimum power output based for that one profile only and uncalibrated towards what wavelength it is for, less precise laser power settings, and no other additional information. Typically, DVD-R burners have to already know how to burn a certain piece of media (and include this information in their firmwares) before they can properly burn to it. New media often is not properly supported.

In addition to the optimum power control profiles, DVD+R also gives four times more scratch space for the drive to calibrate the laser on; more space can only improve the calibration quality. So, in short, DVD+R media exists to simply produce better burns and protect your data better.

And finally, the end of the article…
Finally, after roughly three pages of technical discussion, we arrive at the end of my dissertation on archival quality CD/DVD media. So, you’re probably now wondering, in simple terms, what media do I recommend?

To begin with, I do not recommend CD-RW, DVD-RW, or DVD+RW media in any form for permanent storage. This is mostly a no-brainer, but those discs are meant to be able to be changed after burning, and they are simply unsuitable for long-term archival storage. I also do not recommend DVD-R media due to DVD+R’s superior error correction and burning control.

That said, I recommend Taiyo Yuden media across the board. Taiyo Yuden currently manufactures 52x CD-R, 16x DVD-R, and 16x DVD+R media in normal shiney silver, inkjet printable, and thermal printable forms. Taiyo Yuden may be one of the most expensive (if not the most expensive), but their media quality is unsurpassed. Also, as I mentioned earlier, I recommended buying from SuperMediaStore.com as they are the only online US distributor that guarantees that their Taiyo Yuden media is certified as coming from Taiyo Yuden.

So, what am I using? Due to Taiyo Yuden’s superior media quality, and DVD+R’s superior design, I use only Taiyo Yuden DVD+R media. I recommend this media to everyone who wishes to keep their data for a long, long time.

Update 1: It seems MAM-A and Kodak actually has managed to make a gold DVD, though no one else seems to be manufacturing them (Taiyo Yuden/JVC Advanced Media now makes an archival gold disc, see update 6). However, MAM-A’s gold archival media still doesn’t seem to exceed TY quality (although Mr 60,000 in the comments below puts TY second best to MAM-A). Due to the extreme cost of gold archival media ($2+ a disc) with very little increased protection (if any), I’ll still say TY media is better. I want to see more independent tests on this before I change my recommendation.

In addition, I’d like to mention that Verbatim has been relabeling other brands of disc as their own. If the box/spindle/cakebox the discs come in don’t say they’re manufactured with Verbatim’s proprietary Azo dye (sometimes called Advanced Azo, sometimes not, depending on the product) then they aren’t Verbatim media at all and should be avoided as they may not meet typical home archival standards.

Update 2: (Sept. 19th 2007) Its almost been a year since I first wrote this article. My recommendations for media have not changed, my recommendations for DVD burners have.

Samsung: Samsung is currently producing two drives worth owning, the
Samsung SH-S222AB
(SATA). They’re not considered archival grade, but they’re not bad.

TEAC: TEAC makes an archival drive that is ISO/IEC10995 compliant, and is very expensive. Comes in two forms, external USB DV-W5000U and internal SATA DV-W5000S. I’ve seen DV-W5000U drives for sale for $500, and refurbished DV-W5000S drives for $150-200. This is the elite of drives, and recommended if you’re very serious about 30+ year archival storage.

Update 3: (July 26th 2009) Its been awhile since I updated this article. Pioneer is no longer manufacturing drives worth using. Just buy a Samsung or TEAC drive like I link to above. I’m using two Samsung drives now after my PX-716 finally died after years of service.

My recommendation on TY and Verbatim hasn’t changed, and I imagine it will never change; DVD media will not change significantly from here on out. Bluray in my opinion is not worth switching over to unless you’re storing data that can be measured in hundreds of gigabytes, and at that point you might want to look into archival tape storage.

When Bluray is worth switching over to, I’ll write a follow up article to this one. High quality single layer media will have to drop below 50 cents a piece and Bluray burners will have to become ubiquitous (much like DVD burners are now) before that happens. I’m thinking 2011 or later.

Update 4: (August 3rd 2010) Taiyo Yuden has bought the JVC Media brand and is now operating under the JVC Advanced Media brand. You can now buy TY inside JVC boxes and get your usual TY quality. This site has the conversion of part numbers.

JVC has not bought Taiyo Yuden, and Taiyo Yuden is in full control of this new venture. They merely bought they name so they can put TY products on store shelves worldwide.

SuperMediaStore.com is selling almost all JVC Advanced Media branded TY products in place of the old TY branded ones.

Update 5: (September 27th 2011) A few people have asked about how PIE/PIF scans work.

DVD-R and DVD+R both employ two stage error correction.

PIE (Parity Inner Error) just means error correction was used, PIF (Parity Inner Failure) means the error was unrecoverable using the inner ECC block but still may be recovered using the outer ECC block . On tools that give avg/max/total, max PIE values above 140, or max PIF values above 4* means the disc needs to be replaced but the data most likely isn’t corrupted yet**.

For a burn to be considered still pristine you want max PIE below 20 and max PIF 3 or lower.

Discs will NOT be pristine after 5 years, but there is a fall off of PIF/PIE increasing after 6 months and doesn’t seem to start picking up again until 5-10 years depending on storage environment.

Totals for PIF can be as high as 100k yet have a max of 20, and total PIF can be as high as 1000 but have a max below 3. Max PIE is considered mostly fatal above 280 and can reach as high as 1664, and max PIF can reach as high as 208*.

DVD+R generally will maintain lower values for both due to superior error correction techniques.

* Some tools and/or drives won’t list above 4 for PIF.

** Some tools and/or drives also list PO (Parity Outer) uncorrectable errors. This is for any read that has a max PIF above 4. This indicates a mostly unrecoverable data corruption error, which would effect (if I’ve done my math right) 36k of data (although that doesn’t mean the whole 36k of data is corrupted, just that its corrupted inside of that 36k). This still does not indicate the disc is unreadable, some obsessive ripping tools will try multiple reads in an effort to get a valid read or different incorrect reads that can be merged into a valid read.

Update 6: (January 11th 2013) Taiyo Yuden announced last year that they are now producing an ISO/IEC10995 compliant archival grade gold alloy DVD-R. Sadly, its not DVD+R and I’m hoping they’ll consider making a DVD+R version as well. Not many vendors carry this disc yet.

Also, a few people have asked when I’m going to write that Bluray follow up article. I don’t think Bluray is viable for long term archival storage yet. I continue my recommendation that if you need to store hundreds of gigabytes of data or more, consider archival tape.

Written by
Open Source software architect and technologist. He's just this guy, you know? Follow him him on Google+.
Published in
Transmissions from the Little Blue Marble

Published October 30th, 2006

Comments

1,249 Responses

Patrick,

I have been using Verbatim AZO DVD+R 16x discs (Made in Taiwan) to store info. After reading your info I think I have made a good choice on those but I have also been using Kodak Pro Digital Master Disc (16x).

These claim to last up to 100 years and use a propriety metal alloy along with Misubushi AZO dye according to Kodak,The dye colour is the same just slightly darker. However I don’t seem to see anyone taking about them on the net let alone using them.

The Kodak DMD are made in India. What do you think?, Do you reckon these discs will hold up well in ten years time or is it just marketing talk on their part. I burned all my discs at four speed.

A very good article by the way.

I think they’ll make it at least a few years, but Kodak disc media is not manufactured by Kodak. Since it is made in India, I have doubts of it’s quality. Obviously, it is no TY or Verbatim.

Does it matter what you keep your DVDs in, for the best and longest possible archive storage? For space reasons, I propose to keep mine in one of those disc wallets that unzip for you to slide your discs inside – rather than any kind of jewel case.
Thanks in advance.

As long as the plastic doesn’t have a greasy or oily feeling, you’re probably fine.

Hi, great article! I’ve wondered about a lot of these issues for awhile now, and a friend forwarded this. Now the only question I have left is a rather esoteric one: Mold in hot climates, how do they affect DVD medias inks, and how can I protect my discs from them?

I’ve heard about issues with mold in places like South America. From what I’ve heard, the only way to keep any sort of anything safe (its not restricted to just disc media, and not restricted to just computers) is to store them in an air conditioned environment where the temperature and humidity is strictly controlled.

Its extremely hard to beat mold issues hot humid environments.

I had mould (australian spelling) problems with my videos and a media professional told me to store in the plastic bags that are re-sealable. Keeps mould and water out. Do this with your valuable paperwork too, (in case of a fire where the fire brigade hose your house down). Simple and cheap solution. Good luck!

Hi thanks for the nice article, Sadly it’s way over my head.
I’m tring to make a DVD Data disk to act as a backup for “My Pictures” and “My Files
I’m using Sony DVR-R disks (4.7GB). When using NERO Express 6, near the end of the process it stops and I get an error message “Illegal Disk”.
I also tried it on my NTI CD and DVD Maker 7. With NTI, near the end of the process I get an error message “The disk is incompatible with the current writing”. Neither says what’s incompatible about them.
The blank disk are new and I’ve tried two of them. I treid burning at 4X and when that failed I tried at 2X. Same result. Any idea what I’m doing wrong?

Thanks, … Fred

Without having the discs in front of me, I can’t tell you. Its obviously not the software, as you’ve tried different ones.

Try it on a different computer: if it still fails, that entire batch of discs probably has some issue; if it works, then your drive is failing.

Hello Patrick,

Great article and information. As an all-Mac environment I wish there were CD/DVD disc applications to read the information on a sample disc from a stack that we buy to verify the quality and burn measures.
I would differ on your use of Blu-Ray discs because of the cost only, if not for the idea that the discs are made of inorganic materiels. This alone is making us switch from DVD+R TY’s. For us the initial cost is about $550 but when we have 16 to 24 GB worth of RAW files, the idea of one nice inorganic, continuous containment method is well worth the price difference. This method is of course on top of a NAS.
Cheers, and thanks again, Nicholas.

CDs and DVDs having organic material isn’t that big of an issue. On Blurays, if the seal breaks open, you’ll still have data loss as the layers will start to separate eventually.

Although yes, I do agree, if you need optical media yet have large data sets, Bluray does work quite well. However, I won’t consider switching until I can by TY BD-Rs.

Sorry one more question. Would you recommend external hard drives over DVD media? Just wondering since an external hard drive can save a lot of space. Thanks.

Short answer: No, I wouldn’t.

Long answer: Any medium that can change after the initial writing cannot be trusted by itself. At minimum, you’d need two drives (in RAID1 configuration), and frequently check the array integrity (at least once a month).

Its easier to use an always on-line array in a physically separate location that often checks itself, but also isn’t the only copy of your data… but is expensive and overkill for someone that isn’t doing large scale Enterprise storage.

Not only that, an enclosure with two 3.5″ drives in it is roughly the size of 50 discs give or take. Using DL Bluray discs, that is 2.5TB of storage. So, its not like modern disc media isn’t competitive.

I just with Taiyo Yuden would start shipping their Bluray discs already.

Also, for archival storage of data, what burning speed is ideal (assuming TY DVDs are used and on a Samsung drive)? I know TY carries both 8X and 16X but should we use the rated speed or burn 1 speed below rated (ie. burn at 8x for 16x rated speed and 4x for 8x rated speed)?

Thanks.

Generally, I use this rule. On TY and Verbatim media, I use what is advertised (thus, if it says 16x, I burn at 16x). However, I use one speed less than the maximum for the drive regardless of manufacturer, thus if the drive advertises 16x, I use 12, or if it says 22x I use 16.

Are transparent DVD/Jewel cases the same as the black ones (in terms of quality/the materials used)?

Thanks.

Mostly. I wouldn’t use them for long term storage due to the fact UV light could sneak in. A clear front is totally fine, however.

Thanks for this very informative article, I was looking to archive some home movies & pictures. I had put some movies on some random cheap cds & dvds a few years ago, odd ones seem not to work now, luckily some of the stuff is still on Hard drives and will be able to retreive and this time put it on some quality media.

My best recommendation is to keep multiple copies at least 3 of your valued data and it should be on atleast 2 different types of media DVD, HD, or flash drive. HD are cheap enough these day, to keep multiples and seem to be a little more reliable, well more so than cheap disks.

Can anyone recommend a genuine guaranteed UK seller of TY ?

Thanks Again for article.

Although I do agree with some of your comment, you’re way off on flash. Flash media goes blank after many years of not being accessed due to the nature of how flash works.

If you’re really trying to seriously maintain data, having a RAID that is periodically checked for errors plus DVDs of your data in multiple off-site locations is the minimum you could do.

I can’t recommended a TY seller in the UK. However, watch out, I’ve heard fake TYs show up a lot in the UK.

I have some disturbing news. A couple of weeks ago, I took two DVD-R data discs off a shelf (stored in their jewel cases) which is in a climate controlled studio and attempted to load some of their data, as I was searching for something. Neither disc would read. I tried four different PCs including the one that burned the discs.

I had bought these DVD-R printable silver face media at Meritline a few years back, maybe 2005-6. That data on these discs was written maybe 3-4 years ago and stored since.

I used a program called DVDisaster to try to recover the data. After 49 hours, and noting that over 70% of the sectors were bad on the first of the 2 discs, I had an ISO file to burn. I burned it, but the resulting DVD contained no directory structure and no recovered data.

The media code indicated that the disc was a Samsung BeAll brand disc.

Needless to say, this has completely shaken my trust in DVD or any recordable optical media!

This made me ponder a new design for DVD/CD burners: a more powerful laser that can actually burn pits into the aluminum layer. That would truly be as good as a glass-mastered disc.

Samsung isn’t a brand I’d recommend for media (I have no clue how actually manufactures them, its probably some low grade Chinese or Indian manufacturer), although I do recommend their drives.

That said, this is why I recommend TY and Verbatim: they don’t bitrot after a few years.

Oddly I’ve had a great deal of trouble with Verbatim DVD+R and DVD-R media. I can write them and verify them, but a few months later they will (in some cases) be unreadable.

I’ll give T-Y a try!

Thanks for an interesting and informative article.

Regards, Pete

You should be having zero problems with your Verbatim media. I suspect either your drive is at least partly defective, or your batch of Verbatim media might be counterfeit or (unlikely) defective.

Hi again
Is this true Taiyo Yuden “Aone White Inkjet (Full-face) Printable DVD+R 8X 4.7GB “? They claim it has Mediacode: YUDEN000T02 – http://www.sweburn.com/product.php?productid=42&cat=4&page=1
Jowever they also thinks they are to cheap to be true Taiyo Yuden – http://www.sweburn.com/forum/viewtopic.php?t=451

What do you think?

Could be a counterfeit. TY is hard to find under no name brands.

Can you recommend a bluray burner? Is it coming closer to be worth switching over to?
Thanks

I can’t currently recommend a Bluray burner over any other.

I don’t think its quite worth switching over to until single layer Bluray discs drop below five times what it does for single layer DVD+Rs.

It seems that I have many questions for you. I’ll make them into a single comment

– How important is the DVD case for archival purposes? Is it OK if the case is slim or for example contains space for 10 DVDs such as http://www.supermediastore.com/category/u/cd-dvd-blu-ray-plastic-case-cases?filter=Capacity%3D10+Disc%7C
I’m not sure if the DVDs touching each other would be a concern here.

– Do you also have a recommendation for newbie friendly software for checking the DVDs for errors?

You should try to keep all your questions in one reply.

I’ve seen those 10 disc DVD cases before. They work just like normal DVD cases that have the tray in the middle, but these have four double sided trays. They aren’t excessively thin and shouldn’t be an issue, although rather expensive for just a DVD case.

Buy one and see if you like it.

As for easy error correction software, I don’t know of any. I wish I could suggest one, but its rather difficult to do this without also using a form of forward error correction.

I wish someone would write a program to automate using PAR2 for this purpose. I use PAR2, but it is far from user friendly.

Do you also have a recommendation for newbie friendly software for checking the DVDs for errors?

I have one question for you. I see that you have recommended any black jewel case for the archival DVDs. Does it matter if they are slim cases or not?

Thanks

Hi, and thank you for all the helpful information here. I don’t currently have access to TY or Verbatim at the moment, unless they can be bought at any major known stores like Meijer, Wal-mart, K-Mart, or Best Buy or Radio Shak or something. I am a photographer and musician, taking my own photos and recording my own stuff. I do wish to archive my photos and music and projects on DVD and CD, CD mainly to play in players too. I will try to use DVD+R since I find they will burn in my drives. Are Memorex DVDs o.k. or can I find a good brand at any retail stores? Which program can tell me specs on disks? I use Windows XP mainly. I recorded some music with my band The Fruit Farmers(garage band type stuff with a single mic and a boombox) in 1996 when I was 16 and burned it to a WEWLETT PACKARD SureStore gold looking 650 MB CD-R with a white top label. Has remained good for almost 15 years, even after having to be professionally resurfaced due to scratches and being through a dozen different cases that broke, a few being stepped on while the disk was inside. Have a burned Sony CD-R that still plays great even after being discolored from weathering. Do you think Sony or Memorex CD’s and DVDs are any good? I will look for ones made in Japan and not in China, but it can be very difficult because about every damd thing is made in China now. If you want to hear how bad my old recordings sound you can go to http://www.myspace.com/TheFruitFarmers and thanks again for the helpful info.

OOPS – Looks like I spelled HEWLETT incorrectly. My typing skill sucks.

Hewlett Packard just calls themselves HP nowadays, btw.

In my opinion, anything Sony, Memorex, or HP suck badly. They’re all B grade or worse.

You can buy Verbatim frequently at major stores, but why don’t you just order online through SuperMediaStore using the links I provided in the article?

All other things being equal, are DVD+R media more durable than CD-R media?

I would have expected CD-Rs to be both more reliable and more durable for two simple reasons:

1) Simple scaling laws — CD data is physically bigger, more molecules of dye per bit, wider tracks, etc. This also affects the tolerances needed on the reading and writing equipment.

2) More manufacturer experience — CDs are a long standing standard, surely we know how to make good ones by now.

I appreciate that even if this is true, one still might prefer DVDs, because of the much larger capacity (and DVD media are practically the same price as CD media nowadays). But in my case, the volume of data is small enough that cost per capacity isn’t much of a factor.

So, I’m asking whether, given data that would easily fit on either, whether there are any reasons to prefer DVD+R over CD-R (or at least, any reasons that impact durability of the data).

You have overlooked one important fact: CD (of all kinds) are built with one polycarbonate layer, and the data layer (and the label layer above that) are painted on top. You can alarmingly easily scratch through the label and destroy the data.

Not only this, this is sealed onto the disc, which means several magnitudes of order more surface area for the seal to fail and allow oxygen in to oxidize the data layer and make it useless.

I can take a commercially produced music CD out of a music store and ruin it with no great effort.

DVDs and Blurays (of all kinds) however sandwich the data layer between two polycarbonate layers, and seal the edges of the layers together. You cannot accidentally scrape through the top anymore than you can the bottom.

Due to this very important fact, I can’t suggest CD-Rs except for an absolutely needed basis (such as the target reading device can’t do DVDs, such as a music CD player or a very old computer). Archival storage on CDs is kind of insane.

What is better, gold lacquer, or silver lacquer? Also, are Sharpies okay to write on dvds that do not have a white printable label?
I’ve been purchasing TDKs and have been convinced by reading your article, that I need to switch over to Taiyo Yuden.

Lacquer is a method of sealing something in plastic. Silver and gold are metals used in manufacturing the dyes that are used inside the recording surface. I don’t quite understand your question.

Yes, I use the Sanford Sharpies for CD/DVDs. They do stick to thermal printable discs quite well, just make sure it dries and you don’t accidentally scrape it off (it is difficult, but can be done).

Based on your suggestion, I bought some shiny silver Taiyo Yuden DVD+R discs, from SuperMediaStore.com, for archiving audio files. Just did a successful test burn of the first disc. But I am wondering – I know you mentioned Sanford DVD/CD marking pens, but I just want to make sure: Is it OK to write on these particular discs when there is no “label area” on the top of the disc?

Yes. You can write on thermal printable DVDs without a “hand writable” coating on them. Just be careful not to scratch the writing off, it can be done with excessive scraping (kids, mishandling, etc).

As long as the ink from the pen is dry, it should be difficult to remove it.

I have a suggestion about writing stuff on DVD/CDs. I use a system of writing ONLY numbers on the discs. Then in wordpad I make a index of these numbered discs with the contents. This way I have minimum ink on the disc surfaces. The document is search-able and obviously is backed up too :)

With DVDs and Blurays, this is not an issue. Due to the fact the data layer(s) are sandwiched between two polycarbonate layers, it would be very difficult to damage the disc with a mere disc pen.

I agree with Magellan500 – outstanding article and many thanks to Patrick and the others who have offered their insights.

I have a sony vrdmc10 dvd recorder for photoes and vidio. I would like to purchase the Taiyo Yuden dvd+r disk. Which disk should I buy, silver ink jet, white injet, or shinny silver. thank you

Underneath, they’re all the same discs. Buy Shiny Silver if you plan on marking your discs with a Sanford Sharpie or Verbatim disc marking pen. Buy White Inkjet if you have an inkjet printer with a disc tray. Buy Silver Inkjet if you have an inkjet printer with a disc tray that has white ink (most printers do not have white ink, you usually have to specially buy these specially for disc printing).

I am a computer novice and need some help which would be greatly appreciated. I have a Dell Dimension (4 years old) with a DVD-Ramdrive DVDRW 18x18x12x Type DVD/CD-Rom. I want to transfer photos to a disc and also store videos from a digital video camera. What discs would you recommend for storage?

I would recommend the TY DVD+Rs I mentioned in the article above.

Thanks. I don’t think my burner is capable of using a “layed” disc which is what motivated my question. So I would purchase the TY DVD+R single layer, correct?

A drive that new should be able to burn DL discs fine.

Patrick,

Do you have any experience with the JVC Archival Grade Gold Lacquer DVD+R manufactured by Taiyo Yuden?

From what I can find out, either the discs are not Taiyo Yuden, or TY is handing them lower grade discs (ones they don’t sell under quality brands such as their own or through Verbatim).

Not only that, SuperMediaStore is selling them at the same price. Just buy Taiyo Yuden branded discs and be done with it.

Patrick McFarland wrote: “I do not recommend CD-RW, DVD-RW, or DVD+RW media in any form for permanent storage. This is mostly a no-brainer, but those discs are meant to be able to be changed after burning, and they are simply unsuitable for long-term archival storage.”

Your reasoning is not obvious and may be faulty.

Rewritable media (CD-RW, DVD-RW, and now BD-RE) use a phase-change technology quite different from the dye-based CD-R, DVD-R, and BD-R. Phase-change technology is subject to entirely different aging than organic dye. They share with dye-based media a number of characteristics, such as an inertness to magnetic fields and a vulnerability to high temperatures (the substrate in both cases being plastic). But they differ, being inert to UV light, which dye-based media are most vulnerable to. Short of erasing the media, it is difficult to alter the data on phase-change media without destroying the media entirely.

Your argument against rewriteable media because they are eraseable does not seem at all compelling to me. Far more important is the physical stability of the media.

I understand that you are expressing your own opinion and are entitled to it. But I respectfully disagree with your blanket recommendation in re archival storage on phase-change media. In this I am not alone: archivists also recommend, e.g., DVD-RW over DVD-R for the reasons I mentioned above.

I know that longevity of data stored on, e.g., DVD-R, has been carefully studied, as has that on DVD-RW. I gather that both technologies have claimed lifetimes well above 10 years. But claims by manufacturers give little comfort to users who find that the data are no longer available, and warranties apply to the value of media themselves, not to the value of the data stored on the media.

Most people seem to accept the notion that they should make their selection on the basis of cheapness. And with BD-RE costing about twice as much as BD-R, who among these folks would choose the former over the latter? But doing a good job of archiving data is much more about making intelligent choices and far less about spending as little as possible.

I don’t like media that can be changed because you can accidentally wipe out your only copy.

I do use DVD-RWs for non-permanent storage, such as for installing Linux on new machines (as where I don’t keep a disc handy for that as that disc gets updated too often) and sometimes for mass data transfer.

Its not about how stable the media is, its how archival is supposed to be done. If you need to change your set of data often, build a 4 disk RAID5 or something, then regularly copy it to disc.

If your set changes, toss the relevant discs and burn new ones.

Its not about cheapness (although, yes, with two mediums that have the same failure rate, I’ll choose the cheaper of the two), its about how they’re used.

A write once medium can never be accidentally overwritten or destroyed through the computer, only media failure itself can lose data.

Imagine how many stupid husbands out there have overwritten their wedding videos for a football game. Can’t do that with a DVD-R.

BTW, the UV thing is interesting, but not really that relevant. Discs of any kind should not be outside of their container when not in use. The only time any light (artificial or not) should be on them is between the disc drive and the storage container.

BD-R, DVD-R (dye-based media) versus BD-RE, DVD-RW (phase-change media)?

Clearly Patrick and I disagree on the choice, since he categorically recommends against the latter, and I emphatically recommend against the former. However, the basis for our respective arguments differ widely.

On my part, I say that the data on dye-based media are inherently less stable than those on phase-change media. Patrick’s solution is to ensure that they are stored properly (i.e., secure from UV light).

Patrick’s argument against phase-change media is that they are vulnerable to the bozo. My solution is to ensure that they are stored properly (i.e., secure from bozos).

Perhaps the conservative choice would be to employ both, redundantly. That way, you never have just one copy of the data.

In any event, a comprehensive, systematic archiving strategy for the millennium will entail a great deal more than a choice of data media. Here are some articles worth reading:

“How To Archive Your Thesis/Dissertation/Pro ject Data” (http://www.cs.wright.edu/~jslater/archivingdata.pdf)

“San Diego Supercomputer Center director offers tips on data preservation in the information age” (http://www.eurekalert.org/pub_releases/2008-12/uoc–sds121008.php).

By the way, the Sarbanes-Oxley Act mandates that “electronic storage media must preserve the records in a non-rewritable, non-erasable format”. Since DVD-RW can be erased and DVD-R can be overwritten in a computer, this requirement would appear to disqualify both. Sigh.

S-O only, ultimately, requires Copy-On-Write-And-Keep-The-Original for the context of this discussion. DVD-R isn’t out because sessions (if you’re using sessions at all) do not write over earlier data. Earlier versions of a file can be recovered.

Has anyone done a large scale test of DVD-RW media yet? If it doesn’t stack up to TY, then, well, its not really worth mentioning here, even though it could be technically a superior design.

Organic dyes are unstable, but when properly manufactured and stored, the average life of a disc is going to be much longer than the life of the format itself.

Hi Arthur,

I read your comment(s) with interest, but don’t know whom to trust :)

I found this article as well, it pretty much states the opposite of what you are saying, regarding phase-change discs longevity. Can you comment on that?

Thanks,

Sorry. Here is the link I meant to paste in my previous post: http://www.digitalfaq.com/guides/media/longevity.htm

That article seems somewhat basic and uninformed. The claims for optical media seem to be focused on generic B grade media (such as Indian or Chinese manufactured discs commonly sold under “popular” brands like TDK or Sony or Memorex or whatever).

For stuff that is lower grade than TY and Verbatim, what they say can be very well true. They say 25-50 years for all media, I say that value may actually be too high for media that isn’t TY or Verbatim.

TY and Verbatim should last at least 50 years stored correctly, most likely more.

Patrick:
I enjoyed reading your article and many of the posts.

I have learned from my genealogy research that a photo of an ancestor or a deceased family member is one of the most valued possessions one can have.

Having said that, I’m in my 70s and I’m concerned that the digital images I have, or will have, stored on my CDs and DVDs cannot be read in 100 years or more by any future reader regardless of the storage media. And who will take the time to copy them to fresh media? Some say put the photos on a hard disk (internal or external), some say keep them in on-line storage. But we all know that hard disks are subject to damage and on-line storage is outside the control the control of the user. And when I die and the storage fees go into arrears will they be lost to the dumpster?

Recognising that the price of flash drives is coming down almost by the day, have you or anyone you know, given any thought to storing the images on flash drives? A lot of pictures can be stored on a 16GB or larger drive. This, of course, assumes USB ports will still be around in 100+ years.

I don’t know much about flash drives and their limititations. But they seem worth considering since they are fast and a 16GB drive could hold as much as 3 or 4 DVDs.Would they be suitable for this? Do you know if they are subject to thermal changes, external magnetism or just plain degradation? If they would last longer than DVDs, the costs may be justified. This leads one to think that new sold-state hard drives might be another possibility–not subject to damage, temperature or variations in connection to the computer.

Any thoughts?

I do believe CDs and DVDs can be read in 100 years. If I’m wrong, you have the next 100 years to transfer them to the next format.

Disc media alone has this ability, imo. For example, the DVD spec requires you to be able to read CDs. The Bluray spec is the same for CDs and DVDs, and there will be at least one more generation of disc, and that will be able to read Blurays, DVDs, and CDs.

CDs have been sold for 30 years, DVDs for 15, and Bluray I think is nearing 5. I do believe we’ll be able to read these in 100 years.

I do not trust harddrives or USB drives for permanent offline storage due to their nature: they can be changed. Flash media also suffers from the fact that they will go blank after awhile.

Now, although I don’t trust them for permanent storage, I do believe we’ll be able to continue using USB and modern SATA drives for a very long time. Both standards were designed in mind to be forever forwards and backwards compatible. This won’t change for the next 25 years, and probably not for the next 50.

So yeah, if for some reason disc drives are hard to find in 100 years, you really would have had ample time to see this coming.

Your descendants will take the data with them if they really want it. Just make sure you make multiple copies of this data and send it to geologically distant areas.

Discs could very well last 100 years, but not if they are lost, stolen, damaged, or burned up.

Your concerns about being able to read media long after they were written is shared by most archivists. The Library of Congress itself has many media (magnetic tapes, etc.) whose data are now unreachable because the needed drive mechanism is no longer available. An archivist concerned with the accessibility of data far in the future should plan on copying the data to new media (and verifying its integrity in the process) periodically. Your (or your successor’s) wake-up call will be the emergence of new archival technology.

You ask, “when I die and the storage fees go into arrears will they be lost to the dumpster?” This concern is shared by cemeteries. Historically, a cemetery plot would be recycled once the maintenance fee was no longer paid. The solution would appear to be an annuity that would pay for the maintenance of the data.

As to your question about using the flash drive as a candidate for archival storage, my familiarity with the underlying technology (floating-gate MOS-FET) tells me that you would be skating on thin ice. The floating gate is essentially a capacitor, and any number of effects can discharge it (ionizing radiation for one: think nuclear and cosmic-ray radiation).

You wrote: “If they would last longer than DVDs, the costs may be justified.” With respect, I would like to suggest that this is the wrong attitude for an archivist. The program should be one of keeping up the integrity of the data themselves, rather than the media they are stored on. This means periodically copying the data to new media, which implies an active program rather than simply storing the data once and for all.

Long-term prospects for archival storage of data: media will continue to make the data progressively more compact physically, thereby approaching closer to possible eradication by phenomena such as cosmic rays. Techniques like keeping multiple copies in separate locations and spreading the data holographically out over multiple media will help. Finally, I might mention the Worldwide Web as an aid: publishing the data under Creative Commons could provide as good a guarantee as any that the data will be present after many years, and would make the data useful besides.

I’m sorry if people feel I implied something that I didn’t.

Data should be actively checked up on frequently. Some people do every 1 year, some do every 5. I do every 5 and use multiple pieces of media combined with par2 checksumming.

However, I do feel if there is more stable media invented that lasts longer and has a lower failure rate and also becomes ubiquitous, I will start recommending that purely out of the fact I will have less failures.

This also means that when such a medium is produced, I start migrating my data.

My article does not touch on how to prove the integrity of the data. Although I use par2, I don’t suggest it to people who aren’t familiar with how to use difficult software (ie, its not newbie friendly).

As for storing data using third party storage, I don’t trust any of them because I will outlive a dozen generations of these companies. None of them have really proven track records of safely storing data for long periods of time.

If they go under, so does my data.

They are useful for yet another way of storing data, but do not rely on them as your single and only method.

Now, I’d also like to comment that active storage as a storage method is worth having if you’re into that kind of thing. Although I stated hard drives are not a good offline storage method, they are a good online one if they’re part of an active RAID and they’re regularly backed up to offline media or other geographically separate RAIDs (as used by Enterprise solutions and such).

A lot of my data is stored this way, and then regularly copied to multiple media /w par2 checksums as stated above.

In short, yes, I agree data storage is an active thing. Most people just aren’t really willing to protect their data. My article only mainly serves one aspect of this, but there are many things to consider.

Leave a Reply to Patrick McFarland