Various Forums have suggested that when recording your own DVDs and CDs
that "Skipping" and "Stalling" can occur if "Stick-On Labels" are used.

Various people have commented that by removing the label from a
skipping disk the disk then plays normally again. Therefore I'd like
make a few "Technical" suggestions as to why the label could be causing
this problem.

There are at least 2 theories:


1/ Wobble

The label may be placed slightly off-center thus causing the disk to
wobble more. The laser scanning the disk has the ability to focus the
laser beam on the disk. However the wobble is at a greater rate than
the mechanism can track - hence data corruption.

Observation:

Disks with labels seem to perform better with less problems when used
in "PC DVD and CD Drives".

My theory would be that PC DVD and CD Drives rotate "Faster" than DVD
and CD players. PCs can copy disks at many times the normal play rate.

This is indicated on the drive by statements like " X40 " meaning it
can read the disk 40 times faster than normal play. Thus in this
example a 40 minute CD would read in 1 minute.

This higher "Rotation Speed" makes the "Centrifugal Force" on the disk
greater thus keeping the disk more "Rigid" and wobble less.

I've found that DVDs tend to skip more towards the "Middle" and "End"
of the video - not so much at the beginning.

DVDs and CDs are recorded from the "Inside" - outwards. Therefore the
wobble would be more pronounced on the outside of the disk as it is
further away from the support of the disk's "Clamping Mechanism".

Other observers have suggested that the wobble makes the "Drive
Bearings" hotter thus linking it with Theory Number 2" below...


2/ Temperature

The disk label prevents the top of the disk from "Radiating Heat".

The laser hitting the disk causes local heating. The disk rotation
causes "Eddy Currents" to form which take away the heat from both
sides.

This is called "Scrubbing" and is the same effect that keeps hard disk
drives cool and clean. Dust particles are also scrubbed away and attach
themselves to a "Scrubbing Filter" within the sealed enclosure.

However with one side of the DVD insulated by a paper label there will
be a "Temperature Difference" between one side and the other. This
causes the disk to warm up.

The data is stored in a very thin "Aluminum" layer and being metal
expands. This expansion may then be the cause of data corruption and
skipping.

Observation:

Cold DVDs work more reliably but if played or exposed to higher
temperatures like in a car for example, will skip more if they have
labels on.


Comments and more suggestions related to these theories please.


Harvey Twyman
CV: http://www.twyman.org.uk/CV

wrote:
Various Forums have suggested that when recording your own
DVDs and
CDs that "Skipping" and "Stalling" can occur if "Stick-On
Labels" are
used.

Various people have commented that by removing the label
from a
skipping disk the disk then plays normally again.
Therefore I'd like
make a few "Technical" suggestions as to why the label
could be
causing this problem.

I'd like to suggest that if people are *really* serious
about properly labelling the optical discs they produce,
they simply get something like a Casio thermal transfer
printer. I picked one up for about $60 at a Staple's sale,
and directed that my church get another, one which they did.

One undocumented feature of the Casio thermal transfer
printer is the fact that it pretty well resists the
temptation to put and overly-decorative or complex label on
the disc.

That means that later on, you can actually pick the disc out
of a stack and know what it is at glance, because the
ancient rule of KISS has been honored.

I'm well aware that off-center labels can cause problems, but even
bigger problems can be caused if the label is removed from a disc--the
disc can become completely unplayable as a result. What most people
don't seem to realize is that the data layer of any CD is considerably
closer to the label side than it is to the unlabeled side. With most
discs, the label side is rather poorly protected from physical damage.

So if a label is causing playback problems, a safer approach might be
to try extracting the audio or other content from the disc at 1x speed,
burning a new disc and putting a new label on correctly if the
extraction succeeds.

--best regards

yep,

as a lesson, everyone should take a CD they don't need and scratch the
surface on the label side and see how easily the coating comes off, and
the data is stored directly on the inside of this coating.

Mark

David Satz wrote:
I'm well aware that off-center labels can cause problems, but even
bigger problems can be caused if the label is removed from a disc--the
disc can become completely unplayable as a result. What most people
don't seem to realize is that the data layer of any CD is considerably
closer to the label side than it is to the unlabeled side. With most
discs, the label side is rather poorly protected from physical damage.

So if a label is causing playback problems, a safer approach might be
to try extracting the audio or other content from the disc at 1x speed,
burning a new disc and putting a new label on correctly if the
extraction succeeds.

--best regards


ya.. what he said.. last weekend I had a kid bring in a karaoke CD that
had a yellow post-it on it. The post it, when removed, pulled off part
of the label... AND the actual CD surface!

In article writes:

last weekend I had a kid bring in a karaoke CD that
had a yellow post-it on it. The post it, when removed, pulled off part
of the label... AND the actual CD surface!

If that really happened, I'd complain to the manufacturer of the
"post-it" (surely not a genuine 3M) rather than the CD manufacturer.
Real Post-Its don't have an adhesive that good.


--
I'm really Mike Rivers - )
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me he double-m-eleven-double-zero at yahoo