Help on getting long lasting CD-Roms

Get the best quality dyes and metallic layer in the disk - gold and phthalocyanine eg Kodak Gold Ultima and one or two other brands (Matsui, quantegy. Also, Kodak does still market their gold CD's, but as Pro Audio CD's. Their Gold/silver Ultima's are supposedly about as good. But the reason for a gold foil layer is that gold doesn't oxidize...) Some are also marketed as "archival" this may not mean anything more, just marketed as such. Though some makers may be making the protective top lacquer layer of toughened material to resist scratching. Generally, you get what you pay for - better quality control, disks that are properly balanced (+ less read error) etc.

Remember, the top of the CD, NOT the bottom, is the most fragile! - what you are writing on, sticking labels on, is the actual foil layer - damage it and you're screwed! Store in reasonably low humidity and temperature. 10 to 20c is good (not below -10c) and RH 20-50% (not lower than 10%) No great cycling in either temperature or humidity, so constant temperature and humidity ie hot in the day, cool at night. (one thing to consider is getting on set of CD's vacuum sealed in the sort of foil packs archivists and storing them somewhere cool and dark. We use these for storing Nitrate negatives in our explosion proof (from the inside!) freezer.

Keep in the jewel case( polystyrene, polypropylene or polycarbonate), on edge, no inserts if possible (not acid free) (NOTE - paper envelopes are a BAD idea - generally not archival standard paper and it allows more possibility for warping from outside pressure + in case of water damage, the CD case naturally drains - paper will hold the moisture and stick to the CD). No labels etc (label and glue can cause damage from the chemicals and instable paper, and labels, even circular, increased read errors dramatically). Non solvent marker if necessary on the case, and if on disk, only on the very inner circle where the serial number is.

Store out of light - ie in the dark.

Don't scratch them!

Also, how they are burned also makes a big difference. Higher speed burning/write can lead to more errors. So 1 or 2x write is often better.

Burn to ISO 9660.

In fact one of the biggest areas with longevity apart from the above was error level on the recording side, which depended on a number of factors and got very complicated. Depending on your burning software, running the test disk option actually tests it AFTER burning, to let you know how much error there was (there is always some error). Also, over time, CD burners deteriorate mechanically, introducing more error. And labels of any kind are about the worst immediate cause. They introduce huge read errors straight away. There are errors on all written CD's. They have a pretty extensive and complicated triple (or maybe Quad - I got lost in the Math here...) redundancy system built in. That's why your CD will play with scratches on.

They are still testing accelerated aging in different conditions, but I think they were figuring at least 50-100 years following these type of guidelines. Of course other factors come into effect such as machines to read them and so on, but that is a slightly different topic.

Finally, make one for use and one or two for backup, stored separately - fire, flood, earthquake and theft/vandalism cause more damage than ageing!

May sound complicated, but it's not a lot different than for good storage of Negs and prints. Chances are the CD's will last longer in such conditions than your colour negs....