This is a guide I wrote today when I discovered how to easily transform my scanned drawings into readily usable line art in GIMP. I couldn't find a tutorial like this before when I tried to find one on Google, so I hope this proves useful to anyone trying to give their sketches a little digital flare. ^^
While I know that you can easily color on top of a sketch with a multiply layer, you are otherwise left to clean up all the noise and eraser smudges from the paper if all you wanted was the line art. This method will allow you to extract only the lines from the scan and not have to worry about manually cleaning up anything. This should work for either inked or penciled sketches just fine.
Although the 2.8 version of GIMP is used for this tutorial, it should be generalized enough to work with the 2.6 version as well.
Tutorial and art by
, OC designs featured from a request by =Caipryss
Finished Version of the piece used in this tutorial : [link]