CD-R Blank Media Specifications

• There used to be a distinction between music and computer CD-Rs, but this has since disappeared. cd's image by Horticulture from Fotolia.com

  Commonly referred to as a CD-R, the compact disc is an optical storage media popular for audio and computer applications. The CD-R was introduced by Phillips and Sony in 1988, and represented an upgrade to the earlier compact disc (CD) technology. As opposed to the CD, which could only support a single data writing session, the CD-R allowed information to be added during multiple data writing sessions via the CD-RW format.

Size

• Front-load or tray-load CD players may not accept irregularly shaped CD-Rs. hi-fi cd player image by Yorkie Paul from Fotolia.com

  CD-Rs are commonly manufactured to a thickness of 1.2 mm (0.047 inches) and a diameter of 120 mm (4.7 inches). CD-Rs with a diameter of 80 mm (3.150 inches) are also becoming popular for use in digital camcorders, cameras and personal audio devices. Irregularly shaped, or smaller-diameter CD-Rs, are commonly used for promotions or giveaways; they do not conform to the CD-R industry standard and may not operate in all devices.

Capacity

• Non-standard CD-Rs may not operate in all players. photo de cd image by vanessa martineau from Fotolia.com

  CD-R capacity is rated in either Red Book digital audio minutes for audio applications or in megabytes for computer data applications. Standard 120 mm diameter CD-Rs will accommodate 74 minutes of audio or 650 megabytes of data. The need for more storage space resulted in CD-Rs with a capacity of 80 minutes or 700 megabytes of data. There are also many non-standard CD-Rs on the market, with a wide range of capacities.

Construction

• Due to market demand, CD-Rs can now be purchased in a variety of colors. cd's image by cherie from Fotolia.com

  CD-Rs are manufactured by stacking a layer of polycarbonate plastic substrate, a layer of organic dye, a layer of thin reflective metal and a protective lacquer coating layer to produce the final product. Some discs are manufactured for use in inkjet or thermal printers, or to provide additional handling protection by the addition of another layer to the process. Manufacturers can offer a variety of CD-R product lines by altering layer composition through the utilization of materials such as gold, silver alloy or silver.

CD-R Lifespan

• Lifespan of a blank CD-R is determined by a variety of variables, including quality of construction, handling and storage. On average, the lifespan of a typical blank CD-R is considered to be between 5 and 10 years. Archival quality CD-Rs, which utilize materials such as gold, light-resistant inks and protective layers can experience longer estimated lifespans.