Overprinting
![Knock-outwithout trapping
Knock-outwith trapping
Overprinting
Comparison of a knock-out with and without trapping, and overprinting for perfect and imperfect registration.
Rows are as follows:
1. The cyan (lighter) plate,
2. The magenta (darker) plate,
3. Result with perfect registration (some monitors show slight misalignment), and
4. Result with imperfect registration.](/Images/godic/202501/31/Knockout_trapping_overprinting.svg0021.png")
Overprinting refers to the process of printing one colour on top of another in reprographics. This is closely linked to the reprographic technique of 'trapping'. Another use of overprinting is to create a rich black (often regarded as a colour that is "blacker than black") by printing black over another dark colour.