Today I discovered something weird.
I have a businesscard of 86 mm wide.
When I make a document in Indesign
of 86 mm wide and I put zoom on 100%
and I compare the width on screen with
the businesscard width, the screensize
is a little larger.
Can someone explain that? Is that a
screen issue or so?
The size on the screen has not necessary to do something with the size of the printed output. Imagine, you would compare the same document on the beamer screen at 100% with the real paper. You would terrible fail.
Only if the resolution of the screen is exactly the same value as the program takes as given value it would be exactly the same size.
You can even change the resolution of the screen in your OS. It would also increase the same document at 100% on the screen.
This issue is normal.
In Adobe Acrobat you can define your own resolution (you can calculate it from the screen size to the number of pixels) and so you can get a 1:1 representation on the screen. So my recommendation is, export your file as PDF and check it there.