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This page contains a list of frequently asked questions relating
to our CD duplication services as well as CD in general. If
you feel that you know of a suitable resource and would like
a link from us please send your request to amy@hdc.uk.com
If you have a question
that is not answered on this page please use our enquiry
form.
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How long does the average CD Replication
job take to complete? It varies on the time
of year, through normal production months we are talking about standard
turnaround being 5-9 days, depending upon volume.
In the busier months when there is more work placed at the plant
than it can manage then jobs change to 7-10 days.
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What is pre-mastering?
Stage one - your disc checked for data strength in
conventional duplication industry-standard duplication tower and
stored electronically (hard drive) and then “burnt”
directly back to a CD-R. This tests signal strength and reflectivity
of organic layer on the CD-R and surface for any faults, scratches
or other anomalies.
The firmware that drives the duplication towers
is written around the rules set out for the manufacture of CD's
or DVD's (whichever sub format) and will reject any discs not
made properly; for example if a multi-session disc or “packet
written disc” falls outside the specification and would
fail, the master disc must then be re-written as a single session
finalised disc. The disc is then virus checked using the latest
trend software and is despatched to plant.
Stage two – the same tests are carried
out again but more stringently on dedicated test equipment, also
the signal strength is monitored against other criteria, it is
very rare that a disc that passes stage one test will fail stage
two tests. In addition to the stage on test we also check all
discs for autorun facilities, some discs depending on their content
will not have this but the majority do. We can also create this
facility if a customer requires.
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What kind
of CD master formats do you accept?
We accept all formats known to the professional
duplication history as set out in Philips “books” of
specification – yellow book standard, red book standard etc.
Please see http://www.licensing.philips.com/
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What is
a glass master? Must I have one?
A glass master is an exact reproduction of the
original master, a photo sensitive layer applied to the “glass”
is etched by a powerful laser before being “fixed”
by a chemical process.
This glass master is then processed through a
bath in which an electrical charge is applied to build up a layer
of various metals. Once this layer is around 300 microns thick
(0.3 mm) the process is stopped and this layer is removed from
the glass master and trimmed.
It is this “stamper” (a mirror of
the raw data) that is used in the presses that heats (at great
temperature) the raw material of the disc – polycarbonate.
The glass master in an essential part of
the production process, once made it is stored in readiness to
produce other “stampers” should a re-press be required
or more than 20,000 discs produced.
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What different types of
discs can I have manufactured?
Physical sizes are options but to talk of different
formats is too varied a subject. It is a job for the creative people
who write the content.
There are card sizes, rectangular and rounded edge (Hockey ring
or saddle shaped), 8CM diameter mini or DiDi discs, 12CM diameter
standard discs, 12CM diameter disc body with only the 8CM diameter
data area silvered (called a Creative Disc) and cut discs which
need at least three points to meet the original 12CM circumference
in order to be balanced (still the shape has to reasonably uniform).
In fact there are literally hundreds of different creative concepts.
For more information, please call us on 01274 656565, or email amy@hdc.uk.com
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What packaging
options are available to me for my CD-ROM?
Your packaging options are wide
and varied - for example we can provide specialist packaging production
from over 22,000 different cutting forms! Standard packaging is
also available as print specifications from our existing sites.
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What's the difference between your CD-ROM and CD-R duplication services?
A CD-R disc is manufactured to allow data to be
copied (recorded) by a special device called a CD-R writer. The
CD-R has a recording surface that uses a special dye that can be
ablated by the laser in the writer. When writing to the CD-R disc,
the laser burns the pattern of data into the dye on the recording
side of the CD-R. There is a special grooved, spiral track that
the laser follows when writing the data.
A replicated CD-ROM is manufactured using an injection moulding process
that stamps the spiral track and data into the polycarbonate material
at the same time. A reflective layer of aluminium is then spin coated
onto the disc to allow for the laser in a standard reader to identify
the spiral track and data layout. Once copied the CD-R disc functions
exactly like a replicated CD-ROM disc.
CD-ROM is for projects that require replication
or pressing and generally over 500 units upwards to many, many millions.
They are inexpensive to produce, especially in quantities of 1,000
plus.
CD-R duplication or ‘print and burn’
is for quantities from 100 upwards. As there is no glass mastering
or “stamper” production required, the smaller quantities
are cheaper to produce and offer much quicker turnaround times.
We often produce 1,000 or 2,000 discs as CD-R
production and not CD-ROM production because of the lead time restrictions,
even though they are more expensive.
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Do your cut CD's (shaped CD's) take longer to manufacture than
normal CD's?
Yes, it doubles the production time as it is a
completely different process and is carried out in the same plants.
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