What do I learn in this video?

I learn how to edit an image so that it contains only black.

Why is this step important?

If I do not adjust this setting, black will be printed using all four CMYK colors.

What should I remember?

I need to set CMY to 0 and Black to 100 %, then save the file as a TIFF and disable ICC profiles in the app. This prevents black from being printed using all four colors.