DVDs come in a number of ‘flavours’ which depends on the amount of data you need to reproduce.
Most mass market DVDs which you can buy in the shops are manufactured using an injection moulding process and a single DVD actually consists of 2 discs which are bonded together, called ‘replication’. Depending on the amount of data on the the DVD one or both of the discs (or layers) will be used to store data giving either single layer or dual layer DVDs.
The ‘default’ and cheapest version to produce are DVD-5’s which use a single layer and hold about 4.7Gb of data. Dual layer DVDs are known as DVD-9’s which use both layers and hold around 8.54Gb of data.
DVD Recordable media (DVD-R or DVD+R) as typically used to produce short runs of DVDs are graded in the same way. Single layer DVD-Rs are the default standard and hold 4.7Gb of data. Dual layer DVD-Rs are also available and hold 8.5Gb of data.
The +R or -R designation refers to different types of the Recordable DVD format. For the default single layer 4.7Gb DVD it’s the -R that is regarded as being the best option, giving the widest compatibility on destination DVD players.
Dual layer DVD Recordables are more complicated. Generally we’ve found that +R media is the most reliable choice. However dual layer media does not seem to offer the same level of reliability as single layer media and is disproportionally more expensive.
At the time of writing we suggest that for short runs of DVDs with data in excess of 4.7Gb to split your content over two single layer DVD-Rs rather than a single dual layer DVD+R. If a single 8.5Gb DVD is a must then consider using our DVD pressing service which will give you a pressed dual layer disk which maximum compatibility.