Hi
Booktype is 4 bits of data which tells the player/writer what format the disc is.
Booktyping & Bitsetting are the same. A method for changing the booktype.
Many folk in order to minimise confusion will refer to Booktype, what the media actually is.
Bitsetting as changing from what to what. i.e. DVD+R to DVD-ROM.
As already stated changing Booktype (or Bitsetting) rewrites the first 4 bits. So that on reading the disc the player is led to believe that the media inserted is a DVD-ROM.
This is done to DVD+R/RW/DL.
There is no need for Bitsetting of - media.
Most will tell that it is not possible. Which isnt strictly true. But more than acceptable for our purposes.
DVD+RW can have its Booktype changed even after writing data. Unlike DVD+R/DL which can only be done prior to burning.
Dye colour can have as dramatic an affect on playability.
Mainly down to reflectivity.
Darker is better in these cases.