Using Photoshop’s “Black & White” adjustment vs. rough blue line art.
When I draw a thing, I often first draw it rough using Col-Erase™ blue pencil. Then I go over top and make it look NICER using a dark pencil.
I used to remove the blue pencil from the image in Photoshop by selecting the “blue” channel of the RGB scan and turning that into the line art. That was…