What is the extent of the invisibility the one ring grants? We know that it works on your clothes and as far as I'm concerned on things you are holding such as Sting for example. It does not extend to the patch of ground you are standing on and I also don't believe it extends to people you are touching.

I know, Tolkien uses mostly soft magic systems so it is alright if there is only a practical, intuitive perspective on that matter. But maybe some of you can say more specific things about it or the abilities of magic rings in general!