Issue
We print our artwork on a regular desktop printer and it looks as we want it to look.
However, if we print it with the GT-Jet64 printer, we always have to resize.
Why?
Check the file attributes with for example MS-Paint
In inches
If you cannot deliver files in 316 dpi x 316 dpi, deliver them in 300 dpi x 300 dpi. Not perfect but close enough.