When reading through the terms and conditions at your favorite CD and DVD duplication facility�s website, you come across a term you aren�t familiar with. �All CD duplication projects are done on Red Book standard audio media�. What is the Red Book of audio, what are the media standards it has set, and why is it so important? The Red Book is one of the nine Rainbow Books, which provide universally agreed on specifications for all types of media. The Red Book provides the standards for audio CDs, also known as CDDA (or Compact Disc Digital Audio). There are also Yellow, Orange, White, Blue, Beige, Green, Purple, and Scarlet books in the Rainbow Book set. These different colored books provide audio standards for: Yellow � CD-ROM and CD-ROM XA Orange � CD-R and CD-RW White � Video CD Blue � Enhanced CD, CD+G, and CD-Plus Beige � Photo CD Green � CD-I (Interactive) Purple � DDCD (Double Density Compact Disc) Scarlet � SACD (Super Audio CD) According to the Red Book, a standard CD is 120mm in diameter, 1.2mm thick, and is made up of polycarbonate plastic substrate, one or more thin layers of reflective metal (usually aluminum), and a lacquer coating. The disc is divided into 3 parts � The lead-in area containing the Table of Contents, the program area containing the audio data, and the lead-out area containing no data. The Red Book of was developed in 1980 by Sony and Phillips to specify the physical parameters of the audio CD. This includes the optical stylus parameters, deviations and error rate, modulation system and error correction, and subcode channels and graphics. One other major CD specification set by the Red Book is the form of digital audio encoding taken on by CDs. The parameters set have become a de-facto standard in the CD duplication industry. All in all, most consumers probably won�t be too concerned with the individual technical specifications set by the Red Book. But as a consumer you can take comfort in knowing that there is a high standard of quality being upheld when it comes to your CD duplication, DVD duplication or data CD duplication project. Make sure that when you go to your CD duplication house you ask them if they use Red Book quality CD media.