CDs+which+way+up

CDs which way up

Let us start with how CDs are constructed:-

First: The CD starts with a soft, thick plastic polycarbonate disk that stores the data; the little pieces of data are called “pits”. These pits (millions of them) are “pressed” into the plastic, from the centre of the disk outward.

CDs are read by a tiny focused light called a laser. On top of the data, a thin reflective spray of aluminium coating is applied. (Some manufacturers use gold or silver instead of aluminium.) This layer acts kind of like a mirror and reflects the laser back (after it has read the data) to the CD player’s detector. This is the play side of the disk; it is the shiny side.

On top of that layer, an ultra-thin hard layer of plastic coating is applied. It seals and protects the reflective coating underneath and forms the surface that the label can be applied to.

Finally, the label is applied. Now here’s the important part:

The label itself is very thin – ultra thin – and offers little-to-no protection for your CD. If you scratch your CD on the shiny side, it may become distorted: It could be dirt or a scratch. If it’s on the shiny side and it hasn’t gone too deep, you can generally go a long way towards fixing it by cleaning it or getting some CD scratch remover.

If, however, you so much as breathe on the label side – not quite that bad, but because the reflective layer is so near the surface of the label side, it is a lot easier to damage. And if you damage the label side of a CD, you can pretty much just throw it away.

The label side is easily damaged, so if you damage it, your CD is history. No way to fix it. This makes it seem as if you should place the CD shiny side down.

However, if you damage the shiny side badly enough, it makes the CD unreadable. Granted, it is a bit harder to damage than the other side, but that doesn’t really matter; the point is that it can be damaged beyond repair if you put it down on that side. This makes it seem as if you should place the CD shiny side up.

Quite seriously, it is plainly obvious which side to put a CD down on – NEITHER! You should always put it back in its case. Both sides can be equally as damaging to data on a CD  