Few settings always matters while printing using Acrorip for the images to come out the correct size, Please see below-
1) Check if you have set the correct "Paper Size" for your printer. For instance-
-Correct "Paper Size" for L1800 is 329mm(W) x 650mm(H)
-Correct "Paper Size" for XP15000 should be 210mm(W) for A4 and 329mm (W) for A3.
2) Check if "Page Margin Setup" from "File" menu is correctly set as default or not. Correct default values for "Page Margin Setup" are "Left : 0.000mm" and Top : 0.000"
(Pls note that the end users must not change these default values if his printer has no problem with it's print starting point)
3) Check if he set "Printout -size Revision" from "File" menu correctly or not. Correct default values for "Printout-size Revision" are "Horizontal Size : 300mm" and "Vertical Size : 500mm"
(Pls note that the end users must not change these default values if his printer has no problem with actual print scale)
There must be no scaling up problems if the customers did not change above default values before his printing job.