hopefully this helps
there are probably a lot of different ways of removing blue sketch lines, but this is the best method that I've tried yet.
It should work on red lines too, but I don't sketch with red so I dunno how to remove red lines. It's probably the same, only that in Curves and Channels you remove different colors than you do for the blue lines *shrug*
This is my method. I'd previously learned two methods for removing blue lines, but they didn't completely remove the blue lines, at least not without leaving traces of gray instead of blue or messing up the lineart..
This method that I made completely removes the blue lines! So I thought I'd share this method to make things a bit easier for my fellow Deviants. <3
This works the best if the black lines are drawn with a pen/pigment liner/ink, and not pencil. I think this method would remove some of the details if used on pencil art.. hm... gotta figure out a method for that too..
Hope some of you find this helpful
also, the blue I use is Pilot Color ENO 0.7 leads for mechanical pencils. These are awesome and can be found at [link]
and probably other stores too
I recommend sketching with red (magenta) or blue (cyan) if you like drawing traditionally and coloring digitally, without having to erase your sketch lines with an eraser which often leaves the paper, well, not so white anymore.
I know a lot of professional cartoonists sketch with blue before they ink their work. And it does make digital coloring so much easier.
Another thing you can do, if you want to color your lineart traditionally without ruining the original: remove the blue lines in photoshop like in this tutorial, print out a copy of the black, clean line-art and color the copy
I do it as good as all the time when I want to color traditionally, 'cos I'm afraid of ruining the original ;D
just some tips
feel free to ask me any questions you might have, and I'll try my best to answer them! <3
art and tutorial (C) Elise M. Syvertsen / oomizuao 2011