Since I've started drawing Mount Saint Awesome I've been really interested in how other people make their webcomics. There seem to be a lot of different methods with people doing different parts on and off the computer. Recently I've settled on a method that I'm pretty happy with and I thought it would be fun to share it.
I start with a script and often I'll do really quick (and very poorly drawn) layout sketches, just to get an idea of what I'm going to put where.
Then, I draw the frames on the back of something I printed out and no longer need (usually notes from a class or some research paper I had to read or outdated one sheets from the band) and start sketching the comic. Once it looks good I ink everything with a felt pen (and sometimes a Sharpie for thicker lines). I use a straight edge for most of the straight lines when inking. I like this effect better than using a line tool in Illustrator or Photoshop because it gives some character to the lines. For really thin things like guitar strings I do end up using a line tool later on.
Once the comic is inked I erase all the pencil lines and scan into Photoshop. Here I adjust the levels, so it's just black lines on a white background and clean up any errant lines from the inking stage.
From here I take the scan and place it into Illustrator. Lately I've been making my strips 600 px wide so I just drop the cleaned up scan into a 600px x whatever it works out to be (usually around 1010px) document. At this point the magic happens! I use the Live Trace tool (ignoring whitespace) on the scan. This turns the scan into a vector object of just the black lines, which is pretty awesome. Doing this cleans up some of the line work (my hands aren't very stable) and allows me to color "behind" the ink. Here's what the inking looks like before and after Live Trace:
Note the better "black" and cleaner lines.
At this point I use the pen shape tool in Illustrator to do the coloring underneath the ink layer. I've found this to be a lot faster than using a brush tool in Photoshop, though you end up with flat colors rather than a textured brush effect. Once I'm done coloring I go back with the pen shape tool and add cell shading to give some shadow to the art. This is still something I really need to work on getting better at.
Once the art is done I go in with the text tool and all all the dialog and speech bubbles on top of all the other layers. To make the speech bubbles I do a white ellipse with a 2px black border around and under the text. Then I add 3 new points to the ellipse and stretch the center new point down towards the speaker to make the speech tail.
After making any final shifts or corrections (and usually having someone else spell check things) I save the comic as an 8 bit .png. I've had some color lossyness that I wouldn't have gotten with a 24 bit .png, but the size difference is substantial and with smart color choices the difference isn't really noticeable.
There you have it! From inception to final image. This whole process can take anywhere from 3-6 hours, sometimes more depending on the complexity of the art.
The pictures shown here are from the creation of Mount Saint Awesome #19. Check it out to see the finished product, if you haven't already seen it.