One commonly misunderstood process in the replication process is the difference between Audio and Glass Mastering.
Audio Mastering
We use the best mastering solutions for your project
Once an album is mixed by the Producer it is usually sent to Audio Mastering for compilation of the track list and a final “touch up” of overall Equalization, compression and cleaning of the tracks prior to a production master and Back up master being issued to Pressing-Media’s Glass Mastering Lab.
Glass mastering
Glass Masters are created on site in our Mastering Labs
Glass mastering is performed in a class 100 (ISO 5) or better clean room or a self-enclosed clean environment within the mastering system. Contaminants introduced during critical stages of manufacturing (eg, dust, pollen, hair, or smoke) can cause sufficient errors to make a master unusable. Once successfully completed, a CD master will be less susceptible to the effects of these contaminants.
During glass mastering, glass is used as a substrate to hold the CD master image while it is created and processed; hence the name. Glass substrates, noticeably larger than a CD, are round plates of glass approximately 240 mm in diameter and 6 mm thick. They often also have a small, steel hub on one side to facilitate handling. The substrates are created specially for CD mastering and one side is polished until it is extremely smooth. Even microscopic scratches in the glass will affect the quality of CDs pressed from the master image. The extra area on the substrate allows for easier handling of the glass master and reduces risk of damage to the pit and land structure when the “father” stamper is removed from the glass substrate.
Once the glass substrate is cleaned using detergents and ultrasonic baths, the glass is placed in a spin coater. The spin coater rinses the glass black with a solvent and then applies either photoresist or dye-polymer depending on the mastering process. Rotation spreads photoresist or dye-polymer coating evenly across the surface of the glass. The substrate is removed and baked to dry the coating and the glass substrate is ready for mastering.
Mastering is performed by a Laser Beam Recorder (LBR) machine. These use one of two recording techniques; photo resist and non-photoresist mastering. Photoresist also comes in two variations; positive photoresist and negative photoresist.
While nearly all mastering to glass is done at multiple speeds for sake of plant efficiency (8X or higher is common), single speed glass mastering (also referred to as 1X glass cutting or 1x glass mastering) is offered by a few CD replication plants as a higher quality process. A large number of audiophiles believe this results in truer reproduction[citation needed] although this has remained a matter of controversy for many years.
Supported Formats:
* CD Audio (Red Book) / CD-ROM (Yellow Book)/ CD-XA (Yellow Book Addendum)
* CD-I (Green Book) / CD-Enhanced (Blue Book) / Mixed Mode / Multi-session / CD-I Ready / Video CD (White Book) / Disc At Once (DAO) / DVD-5 / DVD-9 / DVD-10 / Blu-Ray 25Gb / Blu-Ray 50Gb
Services Glass Mastering
Pressing Media enforces the IRMA Anti-Piracy Program. Customers must supply appropriate documentation showing their ownership or license to copyrighted program content on their order. This is referred to as the Intellectual Property Rights form or (IPR). Orders submitted that contain copyrighted material without permission to replicate it from the copyright owner will be declined or reported to appropriate enforcement organizations.
Services Glass Mastering
If you require any further information please do not hesitate contact our mastering department directly toll-free:
1-800-511-8171 or mastering@pressing-media.com.
