This e-mail correspondence ended up being used in the August, 2000 issue of EMedia Magazine in the article entitled "The Shape-Shifting of CD-ROM". The article is about the shaped CD industry in general, and Greg Mince of Custom Cutting Technologies was selected to respond to a letter circulated by Philips concerning shaped CD's.
Philips Concern #1: Many car stereo CD players, due to their special loading mechanisms, face problems with loading and unloading the disc. The disc might not be loaded at all, or if the disc is in the player, it might not be ejected. Such results might cause a costly repair at a service facility.
Mince Response: Shaped discs will not work in front-loading drives and will definitely damage the drive. Everyone is aware of this, and it's just common sense. Most manufacturers/vendors of shaped CDs put a warning label on their discs telling users not to try to load them into slot drives.
Philips Concern #2: Players using tray-loading drives also have great difficulty in loading the disc, since the shape of this type of disc makes it almost impossible to center the disc properly. This might lead to not playing or, even worse, damaging the player and, hence, costly repairs.
Mince Response: True and False. Loading the discs is not generally a problem. Almost all manufacturers of shaped discs will advocate having at least three points of contact. It is actually fairly difficult to misload a disc accidentally. Of course, nothing is foolproof since fools are so ingenious.
Philips Concern #3: Shaped discs also have very large unbalanced features. Although unbalance is currently not specified in the Red and Yellow Books, excessive wear of turntable motors can result and, hence, costly repairs.
Mince Response: True. We do not cut unbalanced shapes. Some other companies might. There are some shapes that just cannot be balanced; Christmas Tree, Raindrop, wine bottle. With drives getting ever faster, these type shapes are doomed from the beginning. However, unbalance is relative to drive speed. Some unbalanced shapes will work in 4x readers, and even 8x readers, unless the shape is horribly out of balance. We try to balance shapes to within 0.003" of center. Out of balance shapes will damage a drive (I have personally ruined a 24x drive with an out of balance disc from overseas). Obviously, it is not in our interest to produce discs that are going to be a problem or damage drives. When our customers are looking at a custom shape, we have them send a request with a copy of what they want the face graphic to be. We develop a shape that will be balanced before the discs are produced. Then we have our customer modify the artwork to fit the shape. We also send out test cuts so that everyone is aware of what the final product will look like and how it will perform when it is produced.
Philips Concern #4: Since the shape of the disc is made after molding and finishing of the disc, the reflection layer at the outer edge of the disc is not being protected by the protective coating. Therefore the reflection layer will possibly be exposed to air, which may be causing corrosion of the reflection layer, finally leading to bad read-out signals and playability problems.
Mince Response: Yes, the metallized area is exposed after cutting. However, it is only a cross-sectional edge that is exposed. Due to this small area of exposure, it is our understanding that there is a finite amount of metal that will oxidize. The chances of oxidation into the discs more than a few thousandths of an inch is doubtful. Since almost all (99 percent) of the discs we see are promotional marketing pieces, long shelf life really doesn't matter. These are not software products that a user will reload year after year. Concerns about edge oxidation are like worrying whether the Land's End Spring 2000 catalog is printed on archive-quality, acid-free paper.
Basically Philips' questions are an engineer's perspective on all the things wrong with a shaped CD. Honest truth, the best design for a CD is round- that's why they designed them that way in the beginning. A shaped CD is a marketing tool. It's fun. It's interesting. It's eye-catching.