extracting lineart from background

i finally dicovered how to properly use the note tool so THIS is the actual tutorial, with words and everything :D!! i wanted to show you some of the ways how to extract the lineart from the background so it would be ready for underpainting, or overpainting, depending what you prefer. i covered background/lineart0 explanation, multiply option, using channels, using clipping mask. i hope it was helpfull and instructive. i apologize for my typing faults. there is a sentence saying: if you made a lineart n