Hi everybody, I've just noticed the conversation, sorry. I won't get into the discussion about consequences for the application now. But you can see in the documentation how (and maybe why) FOGRA 51 was created that way. It is online on eci.org<http://eci.org> and in English. A bit hard to find - it is in the Resources section of the FRED15 project which led to F51 and F52: http://www.eci.org/en/projects/fred15#fred15_project_material The direct links are: FOGRA 51: http://www.eci.org/_media/en/fred15/hanno_hoffstadt_taga2016_v2.pdf The method is a virtual calibration of many real prints to a perfect standard using the spectral model behind GMG OpenColor, and then averaging those spectral data. FOGRA 52: http://www.eci.org/_media/en/projects/f51_f52_beta_doc_handout.pdf FOGRA 52 == FOGRA 52-beta; but FOGRA 51-beta is an older, abandoned approach, so ignore that part please. For FOGRA 52, we had a couple of validation test prints in 2014/2015, but we didn't want to go through the same modelling effort. Instead, we decided that - given the much higher variability of uncoated papers - the FOGRA 52 beta was good enough. Because of the different approach, including empirical Lab shifts, we do not have spectral data for FOGRA 52. Best regards Hanno