The certification test is a digital printing proof that reproduces a generic characterization profile. At our company, we commonly use the FOGRA 39.
The "certification" comes from the fact that the test is subjected to an instrumental control that evaluates the offset tonal values reproduced from the standards set for the Fogra 39 profile. On testing, the presence of the scale allows the machine to carry out the measurements.
Once the instrumental verification and estimation is performed, so that the differences do not exceed the tolerances, it is time for the "certification" test.
At this point, it should be possible to reproduce the test result on a printing press without the need to change the color scales.
In some situations, variables such as the print media and the different characteristics of the printing machine (alignment, dot-gain of the screen, etc.) may require a certain tolerance with regard to the offset from the proof.
Color proofs are also made on flexible and transparent metalized materials.