Premastering for CD/DVD/BD
In addition to accepting physical disc masters, Microforum accepts DDP images for CD and DVD projects and BDCMF images for Blu-ray disc manufacturing projects. These image formats are considered “ready for Glass Mastering” and will not incur any extra fees. These electronic images can also be transmitted electronically by email link or FTP.
If you choose to send a physical master disc, here are some tips:
Blank Media Selection:
Selecting good quality media is the first step to producing a successful pre-master for glass mastering. Our preference is Verbatim product, or comparable brand-name products. Using inferior quality CD-R (or DVD-R and BD-R) media may result in unreadable sectors on the pre-master (the technical term for this type of error is a CU error). Poor media will also increase the number of C1 and C2 errors in your pre-master. C1 and C2 errors, in limited numbers, may not adversely affect your master, as they are generally correctable if there aren't too many of them. However, a CU error is not correctable and almost always requires the pre-master to be resent for Glass Mastering. Note: For Blu-ray glass mastering, BD-CMF images are required. Microforum can convert your BD-R or BD-MV to BD-CMF for you for an extra fee.
The speed at which you burn your media can also affect the number and frequency, of C1, C2, and CU errors on your pre-master. It is recommended that you burn your pre-master at the lowest speed setting available (i.e. 1x or 2x) rather than the maximum rating listed. There are also a variety of CD/ DVD Analysis Software Packages that will diagnose the quality of the pre-master - look for a package that will give you information about C1, C2 and CU errors.
IMPORTANT: If you make multiple copies/burns of your master, successfully analyzing the first copy/burn does not mean that the subsequent copies are error free! Please write the disc as Track at once, or Disc at Once and close the session/disc in the options menu of your burning software program! It is highly recommended that you test the actual copy that you are sending for Replication.
Note: If you are consistently getting a large number of C2 and CU errors in your pre-mastering, and you tried different brand types of blank media with no change in the results, you may have a burner that is not operating at peak efficiency (i.e. it maybe a dust issue, a mechanical problem, or an age issue with the burning device).
Once the tray on your Burner opens and presents the newly minted pre-master, care should be taken to prevent dust, fingerprints or scratches from degrading its surface. Do not touch the recorded side of the media with you finger tips and always handle the media by the edges.
You may want to consider hand-writing your information in the clear plastic area near the hub or use discs with a printable top surface in conjunction with a thermal or inkjet CD printer. We do not recommend applying any kind of label to the surface of your pre-master. However, if you are extremely careful and accurate (use a label applicator) and use the right kind of label, then it can be acceptable. The wrong kind of label can damage a disc and asymmetric labels may throw the disc out of balance, causing read errors. Never apply a label on top of an existing label. You may want to consider instead of a label, writing directly on the surface of the disc, but only if you use a felt tipped pen that is approved for this use. Never use a solvent-based pen on a disc as it can eat through the lacquer and damage data on your pre-master.
The more secure method is to package your Master in a hard shell container, such as a jewel case. Additionally, a bubble envelope or bubble-pack padding is a good way to protect your disc in transit. Although paper sleeves due afford some protection against dust, fingerprints and scratches, they are not recommended for transportation, unless properly wrapped.
Cleaning or repairing a dirty CD-R or DVD-R
If the disc is unique and unreadable and can't be replaced, then use a soft lint-free cloth and soapy water (distilled is best). The cloth must be free of any particles or hard fibres that could scratch the disk. The cleaning agent must be a soap, such as Ivory Liquid and not detergents or solvents such as alcohol. Gently wipe in a straight line from the hub to the outside with a wet cloth (error correction methods are better at correcting scratches and marks that go from the center out) and avoid any unnecessary pressure on the disc surface. Scratched discs cannot be repaired by the use of pastes (toothpaste) and waxes (car polish). The use of these solutions can actually increase read error rates even though the visual appearance of the surface may have improved.