Apertue Albums. Very confused

I need some help with Aperture Albums. I've got a big project and I am trying to create multiple Albums for different output (One for prints, One for Web Gallery, One for my portfolio). I need to rate (and process!) files differently for each type. However, if I just copy files from my master project into a new Album, it inherits all the metadata and any change to it, changes the metadata cross all the Albums.

What do I do wrong? Is there a way around it or i am fundamentally wrong with the intend of the Albums?

Thanks!
KG