Just out of idle curiosity, what is "pressing" a disc? The reason I ask this is related ot the custom discs, they are CDR's. What does pressing involve and how does it make the disc more durable?
Pressed is a mass production technology...analogous to pressing a vinyl record in the olden days. As I understand it the pits that make the 1001010110 stuff are pressed into the foil layer before the plastic bits are assembled. This creates the Silver Factory look of a CD+G
A Custom Disc is burned...that is; a laser light of a specific frequency is focused on a light-sensitive layer creating the pits.
As to durability both technologies claim a minimum shelf life of 10-15 years with a practical life of longer than the technology has existed.
The foil layer is closer to the label side, so be sure to rest discs shiny side down. This also keeps the light sensitive CDR in shadow, which theoretically could eventually make a difference (say after 150 years or so)
A pressed disc is not more "durable", but it does afford more protection from careless handling and scratches.
Pressed discs are discs that are created from the manufacturing process of replication. This is the process in which an audio or software master is turned into a Glass Master, from which a Stamper is created, from which a 'run' of discs are manufactured. A part of the replication process includes paint or ink being applied to the label side of the disc. Not only does this serve to brand/identify/market the product, it also provides a layer of protection for the data.
A burned or unpressed CDR will typically not have any additional coating other than what comes on the original disc. Therefore, it is more critical to take great care with these type discs, as they are more easily damaged than pressed/replicated discs.
With the Sound Choice custom discs - which, of course, are not pressed - we added artwork to market and identify the discs as legal and authentic, and also to provide some additional protection for the disc. However, about 40% of the disc is unpainted, in order to allow the song titles to be printed onto the discs. In an effort to provide more protection, we're also trying to find a protective coating to further limit the possibility of damage due to careless handling.