|
CD-R F.A.Q.
The variety of CD recordable discs
in today's market is enough to confuse all but the most experienced user.
Here is our "CD-R Frequently Asked Questions" or FAQ page for your
information. It contains the latest information and advice we have
available on -- CD recordable discs, labeling and printing issues, and
packaging options.
-
How are CD-Rs different than store-bought CDs?
-
What do "disc write speeds" mean? (16X, 24X, 32X, 40X etc.)
-
What is a "TruSilver Diamond CD-R"?
-
Why are some CD-R discs called "Improved"?
-
Why would I use a "Silver/Blue CD-R"?
-
Are gold CD-R discs better than silver?
-
What about 90-minute and longer CD-R discs?
-
How long do CD-R discs last?
-
What about making CD-Rs for cars and portables?
-
How should I label my CD-Rs?
-
What is a "printable CD-R"?
-
What is a "re-writable CD-RW"?
-
Which CD case or holder is best?
-
Will airport security scan X-Rays hurt my CD-R discs?
That's the list. Now here are the
details...
(1) How are CD-Rs different than store-bought CDs?
A CD-R is a blank "compact disc -
recordable". However, the music or software CD-ROM is a "compact disc -
read only memory". The CD-ROMs you buy in stores are not recordable. They
were never recorded. Instead they were mechanically stamped or pressed,
like the old-fashioned vinyl LP albums.
Store-bought pre-recorded CD-ROMs
use tiny pits or holes arranged in the tracks of the disc to encode the
music, video or game software that you play. In a similar way, your CD-R
burner uses laser-light bursts during your recording sessions to create
tiny bubbles in the tracks around the CD-R. The burner's laser blinks
rapidly on and off, heating tiny areas of the bottom of the disc which
expand into bubbles that closely resemble the stamped pits of a CD-ROM.
Later, when the CD-R is played back, the CD-R is now actually a CD-ROM. CD
players read CD-R and CD-ROM discs equally well in almost all cases. (A
few CD players may have difficulty reading CD-R discs, but playback
problems are usually caused by scratches, poorly applied or too-heavy
off-center CD labels, and discs that have been exposed to heat or UV light
-- discussed below.)
You have probably heard of
several types of CD-ROM discs, including those that contain music,
software, video, photos, and games. On each of these types of CD-ROMs, the
data is formatted differently. CD players are made to be able to read or
decode each of these CD-ROM formats so you can easily use the disc,
without knowing much about its contents. CD-R discs can be burned in the
same formats as CD-ROMs, and played the same simple, easy way. CD creation
software lets you select the final format of the disc you're creating.
After you make a few optional decisions, the actual recording of a CD-R is
usually quite simple. See the manual for your CD creation software for
more details.
Once fully recorded or burned, a
CD-R disc cannot be erased and used over. Therefore CD-Rs are sometimes
called "write-once" discs. There are also erasable "re-writable CD-RW"
discs. CD-RW discs are sometimes called "write-many-times" discs, and can
be fully erased and re-written up to 1,000 times. Unlike CD-Rs, CD-RWs
cannot be played by most CD players. They are for data storage and editing
uses in computers. We discuss CD-RWs in detail under question #12 below.
(2) What do disc "write speeds"
mean? (16X, 24X, 32X, 40X
etc.)
CD-R discs are described by their
recording capacity or runtime length. You can buy both 74-minute and
80-minute CD-R discs. Today most CD-Rs are sold in 80-minute lengths, but
you will see some brands that offer both 74 and 80 minute sizes. The
actual cost of making the discs is about the same. However, some of the
very old CD burners do not recognize the 80-minute CD-Rs, so the short
74-minute discs are still offered by some makers. Both of the discs are
the same physical dimensions or measurements - 120mm (12cm) in outside
diameter, with a 21mm center hole.
CD-Rs are also described by their
write-speed certification. A 2X speed means that the disc can be BURNED or
recorded in 1/2 the length of the disc total runtime or 40 minutes for an
80-minute disc, an 8X disc at 1/8 the runtime, or 10-minutes -- on down to
as little as 2 minutes or less at 48X speeds!
CD-Rs are tested and certified by
their factories to be properly recordable at the rated speed. Today's
fastest write-speeds are usually 40X, but a few companies are beginning to
claim 48X speeds. The most popular write speed purchased in today's market
is the 32X rated CD-R (2002).
In order to burn at a given
speed, your CD burner, your computer and your software must be able to
work at that speed, as a total CD recording system. CD burners come rated
with a triple speed rating, often written like "32X/10X/48X". That
statement would mean that the drive can WRITE CD-R discs at up to 32X,
RE-WRITE CD-RW discs at up to 10X, and PLAY at up to 48X. (To read about
the differences between a "re-writable CD" and a "write-once CD-R", see
our question #12 below - What is a "re-writable CD-RW"?)
Whether or not you actually are
able to achieve those speeds depend on many factors: The disc must be
rated at that speed. Your computer needs to be able to handle data that
fast through its connections, cables, motherboard and hard disc. Your CPU
needs to be fast enough to do the work of translating the music or other
signals you're recording into the encoding used to store the data onto the
disc, and the CD creation software you're using needs to be able to handle
the given speed. Each part of your system needs to be able to do its part
of the job.
Today's 800mhz or faster CPUs,
with fast hard drives and also with state-of-the-art internal motherboard
hardware, are capable of easily handling any 32X or faster CD-R creation
task. However, experienced users often choose to record their discs at a
much slower speed. This gives their system an extra "cushion" to avoid
many burning errors that sometimes occur at the faster speeds.
Since each different software,
hardware and CD-R disc brand or type delivers a slightly different speed
and recording-quality capability, a little experimentation will help you
decide which speed to use. If you change your hardware, software, burner
or other system components, or if you begin using a new type of CD-R disc,
it's time to do a bit of experimentation again.
A TECH POSTSCRIPT:
Bill O'Brien (who writes the
Hard Edge column at
Computer Shopper magazine) wants us to be sure to point out that the
original X-rating applied to drive speed, and was related to 150KB/sec
data transfer rates for each incremental "X" for drives, as opposed to the
time it takes to burn a disc. So, a 2X drive could transfer data at
300KB/sec, and a 4X drive could achieve data transfers up to 600KB/sec,
and so on. He feels that the connection between a disc's x-rating being
expressed as a fraction of its runtime, and a drive's data transfer speed
rating in KB/sec is a mere coincidence.
We want to publicly thank Bill for that
technical reminder. Of course, he's absolutely correct about the 150KB/sec
being the basis for the X-rating for drives. That was the speed needed to
PLAY a music CD in "real time", so you could hear the music as fast as it
was actually being read, decoded into sound, and processed through your
sound system. That basic speed was the original design criteria for a
CD-ROM player's data transfer and processing capability for music CDs.
However, the fact that 1X drive speed related to a 1-to-1 runtime for the
disc is certainly NOT a coincidence. So, when it comes to burning, if you
burn a disc at 2X speed, it takes half the runtime of your recording to
get it down onto a disc, and if you're doing it at 4X, then it takes one
fourth the time, and so on. Basically, faster X-ratings for discs mean that
we can burn your discs at a proportional fraction of the disc's runtime.
Remember, we're focusing here ONLY about burn time for discs, not about
the basic data transfer rating of drives, or other theoretical
considerations. However, whether experienced users and experts like Mr.
O'Brien want to express the speed in KB/sec or in fractions of the full
runtime -- either way you end up with the same facts, expressed different
ways.
(3) What is our
Diamond CD-R"?
Our advanced Diamond CD-Rs
are made to look as much like a store-bought pre-recorded music or
software CD-ROM as possible. You may have noticed that most other blank
CD-R discs have a colored bottom surface, usually a shade of light blue or
green on the bottom. On the top, most CD-Rs usually have a blank shiny
silver surface. Our Diamond CD-Rs also have a silver top, but
their bottoms are completely colorless - just like your music CD-ROMs.
Diamond CD-Rs don't even have a slight hint of color on the bottom. They're
completely colorless to the eye, so all you see from the bottom is the
bright shiny silver top-reflector, just like a store-bought music or
software CD.
The Diamond's colorless
bottom layer contains special plastic material that absorbs laser light
almost as well as the older light green or light blue materials used on
other discs. So, almost any CD-R burner can write to a Diamond disc.
And, once recorded by your burner, the disc will play in CD-ROM players
just like your music or software CDs you bought in a music stores. Of
course they also work fine for storing data or software.
PROs: They look much more
attractive to most people and help you make a slick, professional
impression on your customers, clients and friends. Close to 100% of CD-ROM
players can read and play these CD-Rs perfectly, even at superfast 48X or
60X playback speeds. The colorless Diamond bottoms are available with a
wide range of top surfaces including inkjet printable surfaces.
CONs: They cost a few
cents more per disc. A small number of CD-R burners may not write or burn
Diamond CD-Rs. Even though new 40X write speed CD-Rs are now
entering the market, most Diamond CD-Rs generally burn at a slightly slower
speed than the very fastest light green or blue bottomed discs.
(4) Why are some CD-R discs
called "Improved"?
When CD-R discs were first
invented about 20 years ago, they were made with expensive gold reflector
layers over a dark blue bottom layer that was super sensitive to laser
light. They needed this super sensitivity so that the slow computers,
weakly powered lasers and unsophisticated logic circuitry in the drives
and computers could produce a playable CD disc.
These dark-blue bottomed discs
had a major flaw... if you accidentally exposed your recorded disc to
sunlight or heat, even a small amount from a window or bright office
lighting... they became completely unreadable! You had to protect your
discs in dark, cool storage all the time.
The thick coating of gold metal
on top was used because it was known not to discolor when marked on or
imprinted with logos, etc. Any discoloring of the metal reflector would
make the disc unplayable.
The dark blue dye on the bottom
recording side of the disc was formulated to absorb almost 100% of the
laser light from the existing CD burners of that era. Against the yellow
gold metal of the reflector, the dark blue dye appeared a dark shade of
green to the eye. So, people called these discs "Gold/Green" CD-Rs.
However, as technology improved
over the years, we began to see alloys of silver used for the top
reflector layers. Advanced formulas included traces of other elements with
the silver to make it resistant to degradation from inks and label
adhesives. This reduced the price of CD-Rs, since silver costs less than
1/25th as much as gold. And, silver is actually about 5% more reflective
to laser light than gold, so the total effect of using silver produced a
better CD-R, at a much more affordable price than the old gold discs!
But, we were still stuck with
that dreary old "blue" dye on the bottom of the disc. Now the CD-Rs looked
"silver/blue". Some companies produced a lighter shade of blue which was
less sensitive to heat and UV light than the old dark blue. These
silver/light-blue discs soon became the most popular discs in the market.
Even so, companies continued to look for a much more "stable" bottom dye
formula -- one that would absorb the laser light and produce a clean,
crisp recording -- but, one that would be much less sensitive to normal
temperatures and office lighting. They wanted a disc that would last for
100 years or more in normal use and storage treatment.
Finally, the Mitsui company
discovered a special very light-green dye that was almost a perfect
combination of sensitivity to laser light and insensitivity to UV and
"normal" temperature ranges. They called their new dye "phthalocyanine"
and patented it. Soon other major companies were licensing and
manufacturing CD-Rs using this new "improved" bottom dye.
Mitsui calculated that their new
"improved" discs would last up to 200 years or more in cool, dark storage!
And, users could expect that these discs would outlast any other kind of
CD-R in normal use; in the office, the home, and even (if they were
careful) in their cars!
Because the dye color of
phthalocyanine was very light shade of green (just barely detectable in
normal light), these new "improved" discs were often called "gold/gold" if
they featured a gold reflector on top, or "silver/silver" if they used a
silver reflector. However, after the recent development of so-called "TruSilver
Diamond" discs with their absolutely colorless bottoms, few people still
call these discs silver/silver. Nowadays, the Mitsui-type phthalocyanine
discs are simply called "silver/green", "silver/light-green" or "Improved
Silver".
Improved Silver CD-Rs are now the
best-selling discs in the market. They are still considered the most
stable, longest lived type of CD-R. This makes them an especially good
disc for use with portable CD players, or for use in automobile CD
changers and in-dash players.
(5) Why would I use a
"Silver/Blue CD-R"?
Because you may have to... There
are a few of the older CD players and burners which will not work with the
light green dyes used by the Improved Silver discs, nor with the colorless
transparent dyes used by the Diamond discs. These older drives'
lasers were tuned specifically for the blue dyes being manufactured then.
If you find that you own one of those machines, then you have no other
option but to use silver/blue CD-R discs, or buy a newer model drive.
Almost all new CD burners and players now being sold work perfectly with
either the Improved or Diamond discs. Also, today's CD burners can work
at 32X or faster write-speeds. In addition to burning a longer-lived CD-R
like the Improved Silvers, these machines will save you untold hours in
production time!
Silver/Blue CD-Rs are still an
excellent product, and have been steadily improved over the last several
years. Now made with a more stable silver alloy, and with better storage
characteristics, the silver/blue types of CD-Rs remain a usable product.
(6) Are gold CD-R discs better
than silver?
As explained above, the very
first CD-Rs were made with genuine gold metal used as a top reflector
layer. Gold was chosen because it did not tarnish when exposed to harsh
inks and adhesives used to affix CD labels to the discs. However, because
the gold metal itself added at least 25-cents to the cost of the disc,
there was constant pressure to find a different metal alloy to use for the
reflector layers.
Silver was especially attractive
as an alternative to gold. Silver costs less than one cent per disc, and
is actually more reflective by about 4% than is gold to laser light. The
only disadvantage to silver was in its tendency to degrade or tarnish if
the harsh inks and adhesive chemicals leached through the top plastic
layers down into the metal.
Advances in CD research finally
produced alloys of silver that had traces of other rare metals, producing
a final reflector layer that was very resistant to tarnishing, yet still
had the advantages of very low cost and high reflectivity.
Today, almost all CD-R discs are
made with one of these new silver alloy reflectors, These discs can be
treated almost exactly like the gold-covered discs of the past. Today's
silver alloy CD-Rs should be able to survive 100 years or more of dark,
cool storage, just like the much more expensive gold CD-Rs.
Further, because silver is more
highly reflective than gold, today's silver discs can be burned (and
played) at much faster speeds than gold CD-Rs.
Gold CD-R discs are still
available in limited quantities. They are rated for slower 8X-16X write
speeds, and their costs range from 200% to 400% higher than their faster
write-certified 32X-40X silver cousins.
(7) What about 90-minute and
longer CD-R discs?
Decades ago, CD-Rs were
originally designed in the 63-64 minute size, like the old "optical"
discs. However, in a few years the 74-minute 650MB capacity became the
standard, and soon after that 80-minute became the most common CD-R.
However, the data-length
description built into each CD at the factory is 2 digits long. That means
that theoretically the disc COULD be up to 99 minutes in runtime. Theory
is one thing, but reality is another...
CD discs are read starting at the
center and moving out toward the edge of the disc in a spiral, as the disc
turns on the drive. The reading is done by a small laser and
photo-electric sensor mounted on an arm that moves from the center outward
as the disc is read. Of course there is a limit to this outward motion; it
has to stop somewhere. Some of the older drives were made with an arm that
would only reach out to a distance that corresponds to about 76 or 77
minutes of motion from the center. Those old drives could not accept the
newer 80-minute discs (and, where they're still in use, still can't).
Nowadays, in a similar way, most drives today won't read or write to a
disc that is much more than 82-84 minutes in runtime. Their lasers'
movements are limited to traveling just a bit more than their designers
expected the 80-minute capacity of discs would require.
This arm movement limit is a
physical barrier to how long you can record and then play a CD-R. Very
early in the development of the CD-R industry, people began to "push the
envelope". Some CD burner manufacturers made drives capable of burning up
to 90-minute or even 99-minute CD-Rs. Of course, once they were recorded,
many CD players could not playback these over-limit CDs. So, they had to
be played on the machines that recorded them. At best "over-burned" CD-Rs
playback situation is "iffy". Some web sites that discuss these extra-long
discs can be found by going to...
click here
Other than as a pastime for
technological hobbyists, 90-minute and longer CD-Rs are not really very
popular. If you want to experiment with over-burning, be sure you have
software that is capable of handling 90-minute discs, and that your drive
has the latest drivers and firmware installed. Like most companies in the
industry, we can't help you much in this area. When you go beyond the
"official" 80-minute capacity, you've entered the world of public support
forums and hobbyist chat rooms.
(8) How long do CD-R discs
last?
Today's CD-R discs can last 100
years or more in cool, dark storage. Under normal use (avoiding hot
conditions like automobile interiors and window ledges, other UV light
sources and scratches, etc.) your CD-R recordings should last for many
years -- probably longer than you'll own a player that can play them!
Our "improved" CD-Rs with
light-green bottom layers will be slightly more resistant to UV light and
heat than other discs, and are generally considered preferable for use in
portable CD players and automobiles.
(9) What about making CD-Rs for
cars and portables?
Here's the scoop on how to create
CD-R discs that will have a "fighting chance" to playback flawlessly in
your portable and automobile CD players, as well as your home CD stereo
system and computer drives...
First, you need to realize that
store-bought music CD-ROMs and your home recorded CD-Rs are NOT the same
kind of disc, even though they look very much alike, and are playable in
the same players.
HERE IS WHY:
-----
Unlike store-bought music CD-ROM discs, your recordable CD-R discs have a
special layer that contains a chemical that responds to the heat generated
by a CD burner's laser. That's a very short (microsecond long) recording
laser blast. It passes up through the bottom, then bounces down off the
top silver reflector again almost instantly -- making the plastic even
hotter in that area. This heats up the plastic around the laser beam, and
creates a tiny bubble. When the disc is played back, the CD player shines
a lower powered laser beam up into the discs and scans it. The player's
logic chip decodes these little bubbles into beautiful music. This special
bottom dye layer's material must be very sensitive to the laser heat in
order to produce well defined bubbles for each and every tiny burst the
laser makes.
By contrast, the CD-ROM discs you
buy in music stores are MECHANICALLY stamped like old-fashioned vinyl LPs
used to be. They do NOT contain the heat-sensitive layer like recordable
CD-R discs do. Furthermore, since they do not need to be responsive to a
heat-generating laser burst like CD-R discs, they use an inexpensive
aluminum reflector on top, instead of the much more expensive silver or
gold used by recordable CD-R discs.
When you leave your CD-R discs in
a hot auto interior or portable CD player in the sun, the heat sensitive
layer in the recordable disc responds to the heat microscopically,
softening the edges of the bubbles that encode your music data. This
process may continue over time, until the disc becomes no longer playable.
If you store CD-R discs in the
sun, this process is unfortunately unavoidable. Any disc sensitive enough
to a recording burners's laser to get properly "burned" or recorded will
also be sensitive enough to an automobile's sun-heated interior to get
ruined.
Due to the even MORE sensitive
dyes used in high speed CD-Rs (those rated 24X and above), this problem
can be even worse. And, most CD-Rs you buy these days are 24X or faster
rated, meaning that they are more sensitive than ever to sitting in a
sunlight automobile's "oven".
So, CD-ROM discs and CD-R discs
are made differently. All CD-R discs will be at least somewhat sensitive
to heat and strong UV light, especially if stored for long periods. The
least sensitive disc we sell for heat exposure would be the
"silver/lt-green" type discs, which use a special phthalocyanine recording
layer dye, made to minimize environmental stability problems. However, no
type of CD-R can withstand long exposures to extremely hot conditions such
as the super-heated interiors of automobiles sitting in the sun.
RECOMMENDATIONS:
-----
* Order CD-R discs featuring the "Improved" light green dye on the bottom
recording side. This is the phthalocyanine dye considered most stable and
least sensitive to environmental heat and UV light exposure factors.
* Order the SLOWEST WRITE SPEED
RATED CD-R discs that will meet your minimum requirements from the
available offerings. Those discs have a tendency to be less heat
sensitive. Remember that all discs will PLAY at any speed once they are
properly recorded. Our 16X, 24X and 32X are preferred to minimize possible
problems with heat and UV light.
* Be sure to use "no-wobble"
CD/DVD labels and apply them with a label tool to make sure
they are bubble free and centered properly. This will minimize the
possibility of playback errors when the discs are spun at high speeds to
today's fast new CD players.
* Don't store CD-R discs in a
closed up auto interior exposed to the sun, when possible.
* Also, when you have to leave
them in the car at all, try to protect them inside a well padded and
insulated CD case with a zipper closure, and NOT inside the in-dash or
trunk-mounted CD player.
* Especially avoid leaving the
CD-R discs in direct sunlight, such as on the dashboard or on the seats.
Under the seats is better.
* If possible, roll down a window
above a half-inch on each side of the car and use a windshield sun-shade
to help lower the interior temperature.
That's our best advice for cars
and portable CD-R burning... We hope this information helps you create CDs
strong enough to have a fighting chance in today's popular in-dash and
portable CD players, and that you will enjoy your CD-R discs for years to
come!
(10) How should I label my
CD-Rs?
In a perfect world, you wouldn't.
Even the best paper labels are susceptible to being ripped, torn,
wrinkled, or slip-shod off-center applications, etc.
MARKING -- For many users,
a good way to organize their discs is simply to mark on them lightly with
a water based or alcohol based, soft tipped marker.
PRINTABLES -- Of course,
that's not a very attractive option if you're selling your discs, or
distributing them to clients or business associates. For professional
purposes, the next best option is to print directly onto the top of the
discs using special CD/DVD printers equipped with pass-through trays.
Printing onto CDs or DVDs
requires that the top surface be specially designed to accept the ink,
without smearing. Printable CD-Rs cost about 10-cents more per disc than
the non-printable kind. They come in 2 varieties; for inkjet or for
thermal printers. S
LABELS -- using labels is
still the most popular way to organize and "index" the contents of a
finished CD-R. Your choices vary from high-gloss to a smooth but
non-glossy finish in white paper, or clear inkjet and laser labels, and
new light weight "no-wobble" frosted labels. There are even colored
paper and metal foil labels for those special occasions!
APPLICATOR TOOLS -- if
you're applying labels by hand, you're in for an interesting time of it...
we strongly recommend using an inexpensive applicator tool to help you
apply the labels smoothly and center them properly. A few bucks spent now
can prevent lots of headaches later!
(11) What is a "printable
CD-R"?
Printable CD-R discs (and similar
DVD-R discs) are discussed in the question above.
(12) What is a "re-writable
CD-RW"?
A regular CD-R is a write-once
disc. That means that anything you burn onto the disc cannot be erased.
Ever. By contrast, A CD-RW disc is "re-writable" or "write-many-times". It
is fully erasable, and can be erased and re-used or re-written up to
1,000 times. One warning: it is not a "random access" disc. You can't
erase just parts of it like you can a hard drive. Once the disc is full,
or whenever you want to re-write it, you need to completely erase
everything on the disc and start over again. CD-RW discs are used
primarily for data storage, backups, or for storing different versions of
software, movies, audio tracks and so on. Unlike CD-Rs, they are not
generally used for distribution.
CD-RW discs feature a special
"phase-change" material in their recording layer, that changes from a
crystalline to amorphous states when exposed to different levels of laser
power bursts.
Whereas a CD-R disc uses an
inexpensive organic dye layer to encode their data, a CD-RW disc uses an
inorganic combination of several rare metals (antimony, tellurium, silver,
and indium). This alloy layer is sandwiched between two dielectric layers
to help produce the crystalline phase when exposed to the right laser
power levels. You'll notice that the bottom color of a CD-RW disc is a
medium-dark charcoal gray; very different from the bright silver, light
blue or light green of CD-R discs.
Their complex structures helps
make CD-RW discs much more expensive to manufacture than CD-Rs. Also, the
difference between the phases of a CD-RW are relatively subtle, in terms of
their reflectivity. So, it takes a more sophisticated read/write head to
accurately detect and decode the data on CD-RWs. That sensitive capability
is called a "MultiRead" feature. Normal CD players are not capable of
reading CD-RW discs, although there are a few players with this feature
now entering the market. Today most CD burners are capable of writing to
either a CD-R or CD-RW. Due to their complex features and expensive
materials, expect CD-RWs to cost 2-3 times as much as CD-R discs or more.
(13) Which CD case or holder
is best?
Boy-oh-boy, what a question...
but we do get this question from many users on a regular basis. Here are
the things to consider in choosing a case for your CD-R discs:
DO YOU WANT TO MAIL IT? --
If you want your CD case to also act like a mailer, then the TrimPak CD
Case is your obvious choice.
WANT THE STORE-BOUGHT LOOK?
-- Our "Standard Jewel Cases" are the ones for you if you want to imitate
the way CDs look in a music or software display. They come with completely
clear and clear/black designs, and can hold from 1 to 6 discs. These are
the cases that use the little removable cards or booklets that slide under
the front and under the tray in the back. They also come in lots of
colors.
WANT A RUGGED, UNBREAKABLE
CASE? -- The problem with standard jewel cases is that they break
easily. No way around that with the brittle clear hard plastic they're
made from. Our non-breakable CD cases are made from a flexible,
translucent polymer that resists breaking and cracking.
WANT A THIN CASE? -- We
offer several designs in slender CD/DVD cases -- ranging from our TrimPak
Mailer/Case to 5.2mm MaxiSlim and Double Slimline Cases.
(14) Will airport security
scan X-Rays hurt my CD-R discs?
In today's crazy world, we're
getting this question more and more often. The answer is, at the moment, a
qualified "no". At least in theory, most x-rays merely zip right through a
CD without being absorbed and "burning" the dye layer. Even though the
silver layer does reflect many of the x-ray frequency photons, a CD-R
disc's organic dye layer is designed to absorb a specific (and much lower)
frequency of light from CD burning lasers. Of course, CD-R discs CAN be
ruined due to exposure to UV ultra-violet light from the sun or other
strong sources. This is because that light closely matches the laser
burning light in color or frequency. Since scanning x-rays are much higher
in frequency, they are not very likely to be absorbed by the organic dyes
used in CD-Rs. Of course, who knows what technology may be coming ...
|