Got a hint from another place, and most likely it was Fineprint. When I tried it first, the result wasn't as remembered and expected. Later I remembered the program had a setting for ribbon condition (new, medium, old) and according to a article about the software I that has to do with the printing operation. Switched an old ribbon (which barely prints anything) and tried again and now it was as slow as printing can be and the result was as expected:
