> > But the latest rumour I've heard is that marker pens are NOT OK, and that
>> the ink will eventually eat through the plastic. Is this true? One of our
>> major department stores is now selling a "special CD marker pen", supposedly
>> archival, but I've not seen it.
>
WALT
>It's a rumour. Nice marketing ploy, however, ought to make the
>department store some money.
>
>Hold a CDR up and look at it from the side, notice how thick the base
>layer is. The ink solvent evaporates immediately, and won't touch it.
>The ink itself does not have enough of anything to do so either. Just
>what is going to eat through the base layer?
>
>Before the ink eats through it, you won't have anything to play it. Even
>if that's hundreds of years.
I agree that it's a silly rumor. I've been using Sharpies on my CDs
since the fall of '95 without damage.
It's not the base layer that protects the recording, however. It's
the layer of lacquer on the top, the label side of the disc. CDs are
read -through- the base layer. The pits (or the dye layer in the case
of a CDR) are on -top- of the base disc. On top of that are the
reflective layer and a protective coat. That protective coat is all
that's between the reflective layer and destruction. It -could- be
damaged by a marker if it was too thin or had a weak composition.
I've damaged a CDR by writing on it with a pencil. But the damage
would happen instantly, not later.
The part of a CD you want to protect most is the label side! A good
argument for putting on paper labels.
-Dan Dugan
p.s. thermal printer spine labels from 1995 are almost invisible now,
though the labels I put on discs (in balanced pairs) are still fine.
-dd
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