why this size in print settings

[pierret18811376]

Hello,

I have made a PDF with InDesign, and then I open it in Acrobat Pro.

My PDF document is 135 x 215 mm, but if I go on Acrobat Pro print settings, I have : "document = 134.8 x 214.8 mm". Why this difference of 2 mm ?

[JR Boulay]

This is because the basic unit of the PDF format is the dot.
So any display in another measurement system causes rounding, which explains these small differences.