Slight shifts will occur between the printing, trimming and scoring processes, meaning a perfect registration of the printed artwork to any fold / score lines will not be possible. We recommend to factor this into your design by keeping artwork away from the folded lines by 0.125 inches, or by placing the artwork across the folded line purposefully, so any small shift will not be noticed.
It is not mandatory to keep your text and images away from the folded lines, however you will likely see some portion or all of your order showing shifts similar to the following reference images, which would not qualify for a reprint:
Envelope Potential Shifts
Brochure Potential Shifts