From sitting in the chair to getting out of it but no one can honsetly tell you how long it takes depend son how quickly your artist works, everyone works at a different rate besides no one chooses a tattoo based on how long it takes to do you either want it, or you dont.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.