This is a tutorial I made to describe step-by-step how to create clean lineart even without using a drop of ink! This is one way I create lineart, using my 2B mechanical pencils and my blue mechanical pencil combined! For this tutorial, I'll be using my drawing of Bubbles GA!

Requirements

Photoshop (or any similar program)
Soft, dark pencils, preferably 2B.
A blue pencil, or a light blue colored pencil/crayon erasable to some extent.


Step 1: Sketch it!

First, take your blue pencil or light blue-colored pencil/crayon and lightly sketch out your drawing. Personally, I use a 0.7 blue mechanical pencil, a Pilot Color Eno. It helps if you don’t apply pressure too hard on the paper, so it’ll be easy to erase. Basically, just keep the drawing light for the next step.

Some substitutes I can recommend are colored pencils that can be erased with plastic or kneaded erasers, or special crayons that can be erased to an extent, like Faber-Castell Smart Crayons. Choose light blue whenever possible, because it's the easiest to remove later on.

Step 2: “Pencil-inking”!

When you’re satisfied with your sketch, take a soft pencil (I use 2B mechanical pencils, in 0.5 and 0.7mm) and draw over your blue sketch. Basically, you use your normal pencil to “ink” the blue sketch. It helps if you try to keep your lines crisp and dark so it’ll come out looking clean later on.

TIP: At this point, it really helps if you use a sheet of tracing paper to block your hand from the drawing. Since you’re now using a soft, black pencil, you don’t want to smudge it all over the drawing!

After “pencil-inking” your drawing, you can scan it in the DPI you usually work with. Just make sure you scan in color mode, not in grayscale or black and white!

Step 3: Blue begone!

Now that you’ve scanned it, bring it to Photoshop! And on the window with the tabs for the layers, history, paths etc., choose “Channels” and click on the blue channel. And TA-DA! What happens is that anything that’s blue on the pic will disappear!

TIP: Another way to do this is to adjust the hue and saturation levels (in Photoshop, it’s ctrl+U). You can adjust the blue and cyan’s brightness levels to maximum to get rid of the blue lines.

Press ctrl+A to select the whole image, then ctrl+C to copy it. Then click on the “Layers” tab, create a new layer, and press ctrl+V to paste the image without the blue lines. You should now have two layers: the original background layer, and a layer with the blue lines removed.

Step 4: Adjust the levels!

Okay, so we’ve gotten rid of the blue lines, but we have a pic that’s still a little dirty. What you want to do now is to click on the layer without the blue lines, and (in Photoshop) press ctrl+L to bring up the levels adjustment window. Here, you can adjust the shadows, midtones and highlights so the pic will look cleaner. Adjust it so that the lines become crisp and black and the subtle gray dirt or smudges disappear. You should end up with clean lineart!

Step 5: Color it!

And you’re done! You lineart is now ready to color! Now that’s up to you how you want to color it. But for those who want to know how I color in Photoshop, you might want to take a look my CG coloring tutorial, parts 1-3.