Miniatures, Random

The struggle of miniature books

How come I can’ seem to get the images right?
I’ve been working on a miniature craft room, and I want to make some books. No matter how I change them in Photoshop they won’t get the right size.
My boyfriend, who uses Photoshop in his work will not be able to get it right either.

I’m so frustrated right now.
I will probably give up for now, but I’ll get back to it again soon.
Do you have any suggestions?