The Process - DVDs

There are two ways to create a copied DVD

The first is by 'burning' the data onto a pre formed blank disc (a DVD-R) - as you would with a PC dvd burner. A laser etches the pits of information in to a dye layer contained within the blank disc.
This is called DVD duplication and is sometimes referred to as DVD copying. The product itself is a DVD-r.

The second is by 'pressing' the discs with a nickel 'stamper' produced from a 'Glass Master' in a manufacturing plant. (Similar to, but a much more refined process than the method used to create vinyl records). This process is often referred to as DVD replication or DVD pressing. Amarok supply three different pressed DVD products:-

• DVD-5 has a capacity of 4.7 GB. It is also known as Single-Sided Single Layer.
• DVD-9 has a capacity of 8.5 GB. It is also known as Single-Sided Double Layer (sometimes called Dual Layer).
• DVD-10 has a capacity of 8.75 GB. It is also known as Double-Sided Single Layer. Double sided discs cannot be printed except on the hub inside the lead-in area. Labelling is therefore a problem with such discs.

DVD Duplication
Duplicated DVDs are discs produced by burning information on to recordable discs. They may then be printed using our full colour thermal printers. These printers produce a high quality glossy finish which is extremely durable. The duplication process is usually suited to DVD volumes of 500 or less.

All our duplicated discs are subjected to 100% bit for bit verification with your original master to ensure that they are an exact copy. At this stage in the process, any discs that fail this test are automatically rejected.

This process is more labour intensive and so duplicated discs are more expensive than replicated discs. So if you require more than 500 units and time permits, then it is more cost effective to press DVDs than to duplicate them.

DVD Replication / DVD Pressing
DVD replication or pressing refers to the process of manufacturing bulk DVDs using a stamping and moulding process. (This is the process normally used for Hollywood movies that you buy in the High Street.) The process is usually suited to DVD volumes of 500 or more.

The DVD replication process requires that a “Glass Master” and “stamper” are produced from your supplied DVD master. The production process is very similar to the CD pressing process but there are differences when mastering DVDs compared with CDs, mainly due to the smaller geometries and tighter specifications.
The differences between DVD and CD means that much of the mastering process for DVD needs new equipment including improved glass master preparation, laser beam recording and developing.
The photo-resist layer should, ideally be about 120 nm in thickness (instead of 140 nm for CD) but successful mastering using the same thickness as for CDs is possible. Any defects or variations in thickness of this layer must be kept very small.

Laser beam recording requires a smaller spot size, higher numerical aperture and tighter tolerances than for CDs. Many LBRs designed for DVD mastering use a UV laser (instead of the blue or violet laser used for CDs).

DVD data is formatted differently from CDs and requires new formatting hardware/software to handle the RSPC error correction, 8 to 16 modulation and the higher channel data rate.
Stamper finishing requires more care than for CDs, since tilt (variations in flatness of the final disc) is critical for DVD.

DVD-9 (dual layer) discs require the upper layer (layer 1) to be mastered with the turntable rotating in the reverse direction. Also, the direction of writing will be either from the inside to outside (parallel track) or outside to inside (opposite track), depending on the application requirements.

Once the discs have been produced they will require some kind of image to be printed on them. This could be text only, text and logos or a full colour image across the surface of the disc. With replicated DVDs the artwork on the disc is usually printed in one or two ways, screen printed or offset printed. The quality of each type of print is very high and is usually around 300dpi and produced from a four colour or CMYK artwork file. Specific PMS (pantone) colours can also be requested up to a total of 5 colours. Artwork files may be emailed to us.