Panelling and fitting sockets in it.

[MikeSharp01]

I am making, because the commercial stuff is too thin to act as the actual wall, and fitting V groove panelling in our bedrooms and am not sure what depth I should rout the V grooves. I have looked at commercial panelling and it comes out between 3 and 5 mm deep - I prefer 3mm but is that enough on a 4m run - will it just feel lost. I also have to fit a number of plug sockets and light switches in it and am wondering what the best way to do this as I would like to use dry lining back boxes as there is no structure behind the panelling. Will this look odd with the grooves running behind the face plates? Any thoughts?

[Oz07]

How thick are your boards. 3mm feels more like a scratch than a groove. Id be looking for more like 6mm you will have to do a test piece see what you prefer. I don't think sockets will look bad with the grooves going into them. 

[MikeSharp01]

It's 12mm thick so I can go deeper. I think I will make a sample and see how I feel. 

[Onoff]

What will look odd is if a groove is off centre to a single gang switch/socket.