Getting started
Calibrating your printer
Do this once per printer and save it as a profile.
Print a calibration sheet on ordinary paper. It carries a 100 mm measuring bar and a grid.
Measure the bar with a ruler. If it is not 100 mm, your printer is rescaling the page. Fix that in the print dialog before adjusting anything else.
Then hold the sheet against your cheque and read the offset off the grid. Nudge the fields in 0.5 mm steps.
Save it as a printer profile. You will not do this again on that printer.