a) Digital Ink (with Photoshop or Painter)

I'll just explain this a little... the technique I use when inking directly on the painting program is simple.

What I first do is convert the b/w file into RGB colors, and then color the lines with a cyan tone (cyan is a very light blue as you can see), that will serve me as guidelines. I do this in Photoshop always, I find it a very useful program ^_^

Next, I create a new layer in either Photoshop or Painter, and start inking above my cyan lineart. You can use a hard round px brush (Photoshop), or a soft ink pen (Painter) to do the inking. When the inking is done, just clear the cyan lineart and flatten the file. Presto! digital ink is done ^_^

b) Traditional Ink

I decided for this one to go with the traditional method. So what I do is print a copy in cyan tones over good quality paper, ink it, and then scan it in grayscale or b/w. Since cyan is a very light color, the scanner won't notice the guidelines and so, you'll get a clean black lineart, ready to color!

And so, we got our clean black lineart into our computer program. With Photoshop CS2 I clean it up a little more, deleting unwanted lines or dust dots that might have been scanned accidentally.