Remove Rules

(Despite being a digital tutorial, I've listed this under "Tutorials: Traditional" because it's essential to know for presenting traditional art online, but will never be a concern with purely digital art.)

Scenario: because you absently drew it on notebook paper, your clever image is forever marred by horizontal blue lines, so you upload it as-is. The only thing you can do to remove those lines would be to digitally white them out, one by one, right? Wrong, there's a quick easy way to strip the stripes off your picture.

In Photoshop* go to Menu > Image > Adjust > Hue/Saturation. Select blue, and drag the Lightness dial all the way to the right. Now all the blue in the image has turned white, including those lines. Repeat with cyan to remove them completely, maybe green if it still needs it. Do it with magenta and red if the vertical line is in the image too. Done! Your picture now looks like it was never drawn on notebook paper. Wasn't that easy?

* I'm using Photoshop, but this can be done similarly in other digital art progs. Experiment.

Note: this only works with black line drawings, with pen or pencil. If you used many colors, this will not work for it.