Every printer trims differently. Two identical machines will hand you the same job with a different margin, and borderless in practice means: the picture is enlarged slightly and cropped at the edges. So that you don't find this out on the evening of the event, there is a test sheet and two sliders under Printers → Test print & calibration – stored per printer profile.
The test sheet
The test print carries everything you need in order to judge it:
- Safe area – a frame that must be completely visible. If it is clipped, picture content is being lost.
- Edge gauge – eight bands of one millimetre each. You simply count how many were cut off: that is your crop in millimetres.
- Circle – visibly oval means distorted, so the scaling is wrong.
- Grey gradient – shows banding.
- Colours and skin tones – the actual acceptance test: skin tones stand out immediately, colour bars do not.
- TOP – so it is clear which way round the sheet was.
The two sliders
- Scaling – how large the picture sits on the sheet. White margin on the outside? Raise the scaling slightly, to about 103 %.
- Offset X / Y – shifts the picture. Frame wider on one side than the other? Correct it here.
Then Save calibration. The values belong to the printer profile, not to the booth – a second profile for the same printer with different paper gets its own values. Reset restores the delivery state.
How to go about it
- Load the paper you will actually use at the event. Different paper means different calibration.
- Trigger a test print and really look at the sheet instead of thinking "looks fine" – count the bands.
- Correct the scaling first, then the offset. In that order, otherwise you are chasing two errors at once.
- Save, make a second test print, check again.
Common cases
- White margin on one side – usually offset, not scaling.
- White all the way round – scaling too small, or the device isn't printing borderless. Check in the printer driver first whether borderless is switched on at all.
- Faces too red or too pale – that is not a calibration question but light and printer profile. The test print only reveals it.
- Result changes between two prints – did the paper or the ribbon cassette change? Then calibrate again.