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FAQ - CD ROM
This page contains a list of frequently asked questions relating to our CD duplication services as well as CD in general.
If you have a question that is not answered on this page please email us info@green-cd-dvd-duplication.co.uk.
- How long does the average CD Replication job take to complete?
- What is pre-mastering?
- What kind of CD master formats do you accept?
- What is a glass master? Must I have one?
- What different types of discs can I have manufactured?
- What packaging options are available to me for my CD ROM?
- Do I need a barcode? How do I go about getting one?
- What software applications should I have my CD artwork made in?
- What's the difference between your CD ROM and CD-R duplication services?
- Do your cut CDs' (shaped CD’s) take longer to manufacture than normal CDs?
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.
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.
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/
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.
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 info@green-cd-dvd-duplication.co.uk
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.
Do I need a barcode? How do I go about getting one?
Please refer to our free bar code service.
What software applications should I have my CD artwork made in?
All the ones specified in the print templates.
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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.
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.
Need an answer? Email or call us on 01274 65 65 65
