rabbi-tom* asked about doing artwork on an iPad or Android tablet. In the conversation, I did a quick test by digitally inking a picture I had on hand.

I took the pic on the left (which has horrible color correction, as it's pencil on paper), took a photo of it with my iPad 4 inside Autodesk SketchBook Express, added a new layer, and proceeded to ink with a Jot Classic stylus. The pic on the right is the result.

The thing with doing it, there's two major issues:

First, you don't have any pressure sensitivity. Now, that's not much of a problem with my art style, but if I press down too hard, the iPad's rough pressure sensitivity registers it and SketchBook says I don't want to draw but sample colors instead!

Second, there is LAG. It's just a bit, but it is noticeable. It's not a Cintiq, which I doubt have any lag at all, but still... UGH!

(* A great artist who currently is on my "You've inflicted enough pain on him, don't commission him again!" list. You should commission him instead.)