Selective outlining, or “selout”, is kind of like shading the outline. Rather than using black all the way around, we apply a color that is closer to the color of the sprite itself. Also, we vary the brightness of this outline along the edge of the sprite, letting the light source dictate which colors we apply.

Up until this point, we’ve kept the outline black. And there’s nothing wrong with that, really, since it looks pretty good and it keeps the sprite well-separated from its surroundings. But by using black, we are sacrificing more realism than we might like to, since it gives the sprite a “cartoony” look. Selout is a great way to get around that:

You’ll notice I also used selout to soften the folds of his muscles. Finally, the sprite begins to look like a coherent whole rather than a whole bunch of separate pieces.

Compare this to the original: